As it was called" examinational hell ", the competition of educational selection system is rather acute in Japan. This article tried to introduce the selection mechanism of entrance examination in Japan more completely. According to the results, some conclusions about educational competitions in Japan would be offered as follows 1、The competitions of extrance examination in Japan is as similar as it is in Taiwan. 2、The type of the senior high schools' extrance examination in Japan may be called" district and entrance examination type " , and universitys' may be called" two stages examination". 3、"diversity of examination" is an important tendency of examinational re-form, but it is difficult to say whether the policy can improve these competitive phenomena. 4、"Finally, the author described some theories to explain the factors of competition.