政治過程的平等，乃是憲法上的最主要的要求之一，此一議題曾經呈現於議會議席分配的例子上，也就是對於每一選區的議會議席之重分配必須符合人口的變動。在日本，此乃高度爭論之議題，為此最高法院亦曾包含議會兩院作了數度的判決。其中還為了眾議員的議度分配，作了兩度的違憲判決。而本文正是試著從政治與法律的觀點來探討此一問題。

　　　　　The realization of eqality in political process is one of the major requirements of the Constitution. This issue has been addressed in reapportionment cases. That is , the reallocation per electoral district of seats in the Diet must be in accord with the movement of population. In Japan, these cases are highly arguable. The Supreme Court has delivered several decisions in reapportionment cases involving both houses of the Diet; in two decisions, the Court held unconstitutional the apportionment for seats in the House of Representatives. This paper attempts to discuss the reapportionment cases in Japan from the viewpoints of politics and law.