During the Qin Dynasty, people's living standards had greatly improved compared to before, and the social system had also undergone great changes. After the Qin Dynasty unified the six countries, the local administrative system of prefectures and counties was relatively perfect. In addition, the Qin Dynasty also implemented the system of three dukes and nine ministers, setting up institutions such as Taishi, Taichang, and Doctor to provide a strong guarantee for the development of culture, education, and science. In the cities of the Qin Dynasty, people lived a comfortable and prosperous life. The streets in the city were spacious and the buildings were exquisite. There were special markets and commercial places where people could easily buy and sell goods. The Qin Dynasty also implemented a monetary system, and the purchasing power of the Qin currency was relatively increased. In addition, the Qin Dynasty also implemented a unified legal system to punish crimes. The criminal law system of the Qin Dynasty was relatively complete, including castration and death penalty. In the beautiful life of the Qin Dynasty, people also enjoyed many benefits. For example, Qin Shihuang ordered the construction of the Great Wall for the people to ensure the safety of the country. They also implemented a pension system to provide security for the elderly.