Commodity barcode refers to a symbol composed of a group of regularly arranged bars, spaces and their corresponding characters, which is used to represent certain commodity information. Among them, the bar is dark and empty, which is a reading device used to scan and read bar codes. Its corresponding characters consist of a group of Arabic numerals for people to read directly or input data to the computer through the keyboard. This set of spaces and corresponding characters represent the same information. Commodity bar code is a commodity logo composed of a group of bars, spaces and corresponding digital characters with certain size and color, which represents certain information. "Strip" and "blank" are represented by two colors with different chromaticity and satisfying certain optical contrast requirements. The "bar" is dark and the "empty" is bright. This kind of "bar" and "empty" and the corresponding character "code" represent the same information. The former is for the scanner to read, and the latter is for people to read directly or input data to the computer through the keyboard. After purchasing the goods, the store will input the barcode number, commodity price, enterprise name and other information into the database. When buying goods, as long as you enter the barcode information, the computer can find the goods immediately. There are two kinds of commodity bar codes: ean bar codes and UPC bar codes. At present, ean bar code is widely used in China. The standard version of ean barcode has 13 digits, while the shortened version has only 8 digits. In the standard version of 13, the first few bits are composed of prefix code and manufacturer code, and the prefix code is managed and distributed by ean international. The prefix codes of China are 690, 69 1, 692, 00- 13 in the United States and Canada, 45, 49 in Japan, 489 in Hong Kong and 47 1 in Taiwan Province Province. This is of great significance to identify the origin of goods. At the same time, the difference of commodity prices is identified by different codes, and commodities with different prices cannot use the same code. Therefore, when designing codes, we must ensure the uniqueness of commodity barcodes. The benefits of using bar codes in commodities are not only to prevent counterfeiting and protect consumers' interests, but also to improve the settlement speed and accuracy after purchasing commodities, reduce commodity costs and increase profits. If the country has certain requirements for the printing quality of commodity bar codes, if you find that there are problems with the printing quality, such as fuzzy and rough printing, uneven spaces, red bar codes and so on. Then the barcode of this commodity may be fraudulent, and then there may be something wrong with this commodity. New technology of integrated data acquisition and processing. Using bar code scanning is the general trend of future market circulation. In order to make goods circulate freely and widely in the world, enterprises must abide by the relevant provisions of commodity bar codes whether designing, manufacturing, applying for registration or using commodity bar codes. At present, ENA barcode, UPC barcode, 25 barcode, cross barcode, Kudba barcode, Sanjiu barcode and 128 barcode are commonly used in the world, among which EAN barcode is the most commonly used commodity. EAN commodity bar code, also known as general commodity bar code, is formulated by ean international and is widely used in the world. It is the most widely used commodity bar code in the world. At present, this commodity bar code is being used in China. EAN commodity bar codes are divided into EAN- 13 (standard version) and EAN-8 (abbreviated version). EAN- 13 general commodity bar code generally consists of prefix, manufacturer code, commodity code and check code. The prefix code in commodity bar code is used to identify the country or region, and the code is given in ean international. For example, 00-09 stands for the United States and Canada. 45-49 stands for Japan. 690-692 stands for Chinese mainland, 47 1 stands for Taiwan Province Province and 489 stands for Hong Kong Special Administrative Region. The empowerment of manufacturers' codes is organized by article codes in various countries or regions, while in China, the National Article Coding Center gives manufacturers' codes. Commodity codes are codes used to identify commodities, and the right to assign codes is exercised by the product manufacturers themselves. Manufacturers themselves decide which Arabic numerals to use for their products according to the prescribed conditions. At last, the 1 parity code is used to check the correctness of the L- 12 digital code from the left in the barcode. The coding of commodity bar codes follows the principle of uniqueness, so as to ensure that commodity bar codes will not be repeated in the global scope, that is, a commodity item can only have one code, or a code can only identify one commodity item. Commodities with different specifications, different packages, different varieties, different prices and different colors can only use different commodity codes. The standard size of commodity bar code is 37.29mmx26.26mm, and the magnification is 0.8-2.0. When the printing area allows, the barcode with magnification of 1.0 should be selected to meet the reading requirements. The smaller the magnification, the higher the printing accuracy. When the printing accuracy can not meet the requirements, it is easy to read the bar code. Because the identification of bar code is realized by the color contrast between bar code and blank bar code, generally speaking, as long as the color can meet the requirements of contrast (PCS value), light color can be used as blank color, such as white, orange and yellow, and dark color as bar, such as black, dark green and dark brown. The best color scheme is black stripes and white spaces. According to the practical experience of bar code detection, red, gold and light yellow should not be used as bar code colors, and transparent and gold should not be used as blank colors. EAN-8 commodity bar code refers to the 8-digit commodity bar code used for identification, which consists of 7-digit commodity item code and 1 digit check code. The birth of commodity bar code greatly facilitates the circulation of commodities, and modern society cannot do without commodity bar code. According to statistics, at present, there are 500,000 kinds of products in China that use the international commodity bar code. After China's entry into the WTO, enterprises will surely win more space for activities on the international stage. To keep up with international practice and meet the needs of international trade, enterprises should not mistreat commodity bar codes.