According to personal library data, the ancients often called the occupational category 72 lines. With the development of society, there are more and more industries, so that there are 365 lines today. At present, there are no accurate statistics on how many industries. But according to the five elements, there are nothing more than gold, wood, water, fire and earth. Some industries have the characteristics of second-line, third-line or even five-line, and can only be divided according to the primary and secondary characteristics of each line, so we should use them flexibly in practical application, and don't stick to this.

Five elements belong to the gold industry: steel industry, metal building materials, etc. Five elements belong to wood industry: wood, wood products, etc. Five elements belong to water industry: fishery, aquarium and so on. Five elements belong to fire industry: catering, restaurants, etc. Five elements belong to local industries: local characteristics, real estate and so on.