First of all, in form, the Qin dynasty implemented the county system, which divided the world into 36 counties, while the Han dynasty implemented the parallel system of counties and countries, that is, counties and countries existed at the same time.
Secondly, the original intentions of the two dynasties were different. The Qin dynasty was to strengthen centralization, and the Han dynasty was to avoid the tragedy of the demise of the Qin dynasty. At the same time, the county system was adopted to strengthen centralization, the enfeoffment system was adopted, and the governors with the same surname were used to avoid local rebellion.
In addition, the roles of the two dynasties were different. Qin's county system fundamentally denied the enfeoffment system, broke the enfeoffment system and separatist regime since the Western Zhou Dynasty, strengthened the central government's management of local governments, helped prevent the division of local separatist regimes, and effectively safeguarded national unity. At the beginning of the Han Dynasty, the regime implemented the county-state parallel system, which expanded the autonomy power of local kingdoms, but also increased the burden of the central government, so the county-state parallel system at that time played a great role in promoting the development of local economy.
Finally, the disadvantages of the two dynasties are also different. Due to the high concentration of power, the county system in Qin dynasty led to boiling public grievances and was eventually overthrown. The parallel system of counties and counties in Han Dynasty can avoid local rebellion to a certain extent, but with the passage of time, the power of vassal kings is becoming stronger and stronger, which will pose a threat to centralization.
Generally speaking, there are obvious differences between the Han Dynasty and the Qin Dynasty in history, including forms, original intentions, functions and disadvantages.