Abstract：There are various opinions about the victory and failure of the war between Greece and Persia among the scholars. The article points out that different political system is a crucial factor for Greece defeating Persia, that is to say, the advantage of Greek democracy which is superior to Persian absolute monarchy makes Greece successful. Morale, strategies and leaders affect the cold weapon war mostly. Greece and Persia are different in the three aspects above. The basic reason of this difference is from the divergent political systems.
