The first statement: The main industries in China in the Tang Dynasty were "36 lines", namely: butcher shop, palace powder, ready-made clothes, jade, jewelry, silk, paper, seafood, fresh fish, stationery, tea, bamboo and wood, rice wine, ironware, ancient embroidery, needle and thread, soup shop, drugstore, bookbinder, clay and glutinous rice. Tsui Hark said in Clearing Money, Agriculture, Industry and Commerce: "Thirty-six walkers, various occupations. As far as the division of labor is concerned, it is 36 lines, 72 lines, and 360 lines ten times. " It can be seen that "72 lines" is a virtual indicator, and the 72 lines or 360 lines that people often say today are not specific numbers. In fact, the division of labor in social industries has far exceeded the 72nd line.

The second way of saying it: China has always used idioms, such as 369, 36 and 72.

There will be seventy-two changes in the Monkey King, and no one has counted those changes, so a large number usually means more or more comprehensive.

According to Qing Bo Magazine in Song Dynasty, there were thirty-six industries in China in Tang Dynasty, namely, meat shops, palace powder shops, ready-made clothes shops, jade shops, jewelry shops, silk shops, paper shops, seafood shops, fresh fish shops, stationery shops, tea shops, bamboo shops, rice shops, iron shops, embroidery shops and sewing shops.

Tsui Hark said in the book Clearing Money, Agriculture, Industry and Commerce: "Thirty-six walkers have their own occupations. As far as its work is concerned, it is 36 lines, doubling is 72 lines, and ten times is 360 lines. " Tian Rucheng's Notes on Traveling to the West Lake said: "There are 360 lines in Hangzhou, each with its own dialect."

According to this, people often say 72 lines, 360 lines and so on. These are not the specific figures of the industry, but the general names of all walks of life.