The general characteristics of modern Western Political Philosophy shows that the philosophical basis of politics lies in human reason with historical，empirical and scientific characteristics. The obvious disadvantage is those of non-ethical and Nationalism. On the Rational basis，Xunzi thought about the basic problems of political philosophy，such as the construction of political system，the source of power，the operation of administration，the legitimacy of politics. It also has the basic points of political philosophy，such as historical，empirical and scientific. Xunzi was the first thinker in the world to think rationally. So Xunzi can be called the first person of political philosophy.