Reason: The peasant war was turbulent at the end of Qin Dynasty. Compared with the military strength of Xiongnu in the north, the battle between Chu and Han was not superior, and it was urgent to recuperate and rebuild their homes.

Main measures: implementing the contract system; Reward agriculture and sericulture; Reduce rent and interest; Carry out the policy of putting agriculture first.

Function: The Han Dynasty won precious time, strengthened its national strength, and emerged a prosperous time for the founding of the People's Republic of China, which laid a strong material foundation for Emperor Wu of the Han Dynasty to drive Xiongnu to the north.