With the popularity of intermarry, different kinds of problems about it gain attention from specialists.On the basis of gathering and analyzing the 1% sample data of the 4th census in 1990, the author studied on the intermarry of 18 national minorities whose population are over one million.This thesis includes, the comparision of gross intermarry rate and standarized intermarry rate between those minorities, and the intermarry rate on sex and age.