Abstract: RAPD (Random Amplified Polymorphic DNA)was used with 28 primers to analyze the genetic variation among the sires and the dams of AA，Avain，and Cobb chickens in this experiment．The results show that the average similarity coefficient of the 6 groups is 70.7％．the dams of Avain and Cobb chicken share the highest similarity coefficient at 81．0％．and Avf and AAm share the lowest similarity coefficient at 6 1．2％ ．And the similarity coefficient within the breed is not necessary greater than that of breed to breed，showing that the correctness of the present broiler breeding program，and implying that the crossbreeding of Avf and AAm will attain the maximum heterosis．DNA marking technology provides methods for studying the genetic materials of foreign breed chickens，and it is also the important references for selecting broiler breeds and crossbreeding．