Pre-Qin: The emergence of commerce ① Reasons: People in Shang Dynasty were famous for being good at business and formed a fixed occupation. Later generations called people engaged in business activities businessmen. During the Spring and Autumn Period and the Warring States Period, the situation of government controlling commerce was broken, and the social status of businessmen was improved. ② Overview: Shang Dynasty: "merchants" appeared, and commerce was controlled by the government. During the Spring and Autumn Period and the Warring States Period, the situation of government controlling commerce was broken, the social status of merchants was improved, and many commodity markets and big businessmen with strong assets appeared everywhere. For example, Fan Li 2, Qin and Han Dynasties: Preliminary development of commerce ① Reason: Qin Shihuang unified currency and weights and measures and built ruler roads. The recovery and development of social economy in the early Han Dynasty (the main reason), and the opening of the Silk Road on land and at sea in the Han Dynasty (II) Overview: "The law is cheap, the business is expensive, and the business is rich" shows that business has developed under repression. Foreign trade has begun.