In practice, enterprises can gain market dominance or even monopoly through legal means. For example, the state authorizes an enterprise to enjoy the exclusive right to operate a certain industry, and this privileged enterprise is naturally a monopoly enterprise. Enterprises can also gain market dominance through intellectual property rights such as patents and copyrights. For example, Microsoft has gained a dominant position in the software market all over the world through intellectual property rights. Although the anti-monopoly law does not oppose legal monopoly, legal monopolists are also not restricted by competition, so it is very likely to abuse market dominance, damage market competition and harm consumers' interests. Therefore, the state must strengthen the supervision of those enterprises that have achieved monopoly or market dominance in the market. 1997 the U.S. department of justice accused Microsoft of violating the U.S. antitrust law, which is an important case in this regard.

The case of Microsoft shows that those enterprises that occupy monopoly or dominant position in the market will be more strictly controlled by the government. In other words, if the same behavior of restricting competition occurs in different enterprises, it will have different legal consequences. For example, when consumers buy Changhong TV sets, if the seller asks them to buy a Changhong brand tape recorder or other products at the same time, consumers will generally not be connected by the seller's unreasonable request, but will turn to buy Haier, TCL or other brands of TV sets. This shows that in the competitive market, tying behavior generally does not cause serious adverse consequences to consumers. However, when consumers install telephones, they will not install them if the telephone office asks them to buy a designated telephone. This tying behavior has caused serious adverse effects on the market. On the one hand, it will seriously harm the interests of consumers, because they have no chance to choose other products; On the other hand, this behavior will also seriously damage competition, because it will bring serious adverse consequences to the marketing of some enterprises. Therefore, the regulation of anti-monopoly law on market behavior is mainly aimed at monopoly enterprises or enterprises with dominant market position.

In China, the enterprises that abuse market dominance are mainly public enterprises. For example, the post office forces users to allocate telephones, the power department forces users to buy their designated distribution boxes, the water company forces users to buy their designated water supply equipment, and the gas company forces users to buy their designated gas stoves and water heaters. There are other manifestations of abusing market dominance, such as overcharging, that is, asking consumers or users for unreasonable monopoly prices; Dumping at a low price, that is, selling goods at a price lower than the cost, in order to squeeze competitors out of the market; Price discrimination refers to the use of different price terms for counterparties in the same position, which makes some enterprises at a disadvantage in market competition. In addition, there are boycotts or rejections of transactions. For example, a chemical company that dominates the market refuses to provide a chemical raw material necessary for the production of drugs. In this case, enterprises that are refused to supply may be squeezed out of the market. The legal consequences of abusing market dominance include stopping illegal activities and imposing fines on illegal enterprises. In addition, the victim can also claim compensation for civil damages. In the United States, the court can also split monopoly enterprises, with the aim of turning monopoly markets into competitive markets. U.S. Court 1982 Transfer of AT&T Company (AT&; T) Divided into eight parts, it broke the monopoly of telecom industry at the earliest time in the world.

(4) Prohibition of administrative monopoly.

Administrative monopoly means that the government and its subordinate departments abuse administrative power to restrict competition. In fact, whether in China or abroad, in the past, present or future, the government's restriction of competition is the most harmful behavior to competition. Therefore, when we study the anti-monopoly issue, we should not only pay attention to the restrictive behavior of enterprises, but also pay attention to the behavior of the government to prevent them from abusing administrative power to restrict competition.

Due to historical and institutional reasons, the former Soviet Union and eastern European countries paid special attention to the issue of administrative monopoly. Article 6 of the Law on Prohibition of Monopoly and Unfair Competition in Enterprise Activities promulgated by Ukraine and People's Republic of China (PRC) 1992 clearly stipulates that the government and its subordinate departments shall not adopt a discriminatory attitude towards enterprises for the purpose of restricting competition, such as prohibiting the establishment of new enterprises in a certain economic field or restricting the production of certain activities or products of enterprises; Forcing enterprises to join enterprise groups, or forcing enterprises to provide cheap products to some enterprises; Or prohibit * * * and a certain region of our country from selling goods from other regions, thus leading to the monopoly of some commodity markets; Or provide tax or other preferential treatment to individual enterprises, so that they are at an unfair competitive advantage compared with other enterprises, and so on.

At present, China's administrative monopoly is mainly manifested in industry monopoly and local protectionism. Industry monopoly refers to the abuse of administrative power by the government and its subordinate departments, which restricts the market access of operators and excludes, restricts or hinders market competition. This is especially manifested in some administrative companies that integrate administrative management with production and operation, large enterprise groups that undertake industry management tasks, and some enterprises that are affiliated with this bureau and that department and enjoy preferential treatment. By virtue of the privileges granted by the government, these enterprises have competitive advantages that ordinary enterprises cannot have, and they are in an artificial monopoly position in the production and sales of certain products or the procurement of raw materials, which unfairly limits competition. This phenomenon is called "e-commerce". Local protection is mainly manifested in the fact that local governments prohibit foreign goods from entering the local market or prevent local raw materials from being sold to other places, thus dividing the market that should be unified nationwide into small local markets. For example, in order to prevent foreign fertilizers or other products from entering the local market, some local governments have specially issued local documents to prohibit local units and individuals from marketing foreign products, and even confiscate or impose fines on operators who arbitrarily market foreign products. In order to prevent foreign beer from entering the local market, some places require local residents to drink "hometown wine". In some places, in order to prevent foreign-made cars from entering the local market, foreign products are charged at will.

As China is currently in the transitional stage from a planned economy to a market economy, the restrictive competition behavior of enterprises is often administrative. For example, the so-called "industry self-discipline price" from 65438 to 0998 introduced by some domestic industries. No matter how to explain "industry price self-discipline", it should be regarded as the behavior of government departments conniving at enterprise price coordination, which is a mandatory price cartel. China association of agricultural machinery manufacturers Agricultural Transport Vehicle Branch, which was the first to implement the industry self-discipline price, even fined Shandong Shifeng Group for not implementing the industry self-discipline price. But from the essence of market economy, it is unreasonable to force enterprises to sell products according to the so-called industry self-discipline price, because the basis of industry self-discipline price is the average cost of the industry. Since it is an average cost, this cost is definitely higher than the individual cost of some enterprises with good economic benefits, which limits the price reduction of these enterprises and makes them lose the opportunity to expand production.

Administrative restrictions on competition not only seriously harm the interests of consumers, but also seriously harm the interests of enterprises. We can imagine that if Santana cars produced in Shanghai can only be sold in Shanghai and Fukang cars produced in Hubei can only be sold in Hubei because of local protection, it will be impossible for these enterprises to expand production, realize economies of scale, and thus improve their competitiveness. In addition, the abuse of administrative power also provides opportunities for some government officials to abuse power for personal gain and trade power and money, which leads to corruption and damages the image of the government to some extent. Therefore, the anti-monopoly law should regard anti-administrative monopoly as an important and urgent task.