Genetic diversity in Xuwen and Hainan yellow cattle and Holstein cows based on protein polymorphisms was studied with starch electrophoresis in this experiment.Among 40 gene loci of 36 blood proteins(enzymes),the same thirteen polymorphic loci in both Xuwen and Hainan yellow cattle and eleven polymorphic loci in Holstein were found.The percentages ofpolymomhic loic in Xuwen and Hainan yellow cattle both were 0.325,averageheterozygosity was 0.141 in Xuwen yellow cattle and 0.132 in Hainan yellow cattle,and the percentage of polymorphic loci and the average heterozygosity in Holsteinwere 0. 275 and 0.099 respectively. The results showed that genetic diversity was rich inXuwen,Hainan yellow cattle and Holstein cows and that both pereentages ofpolymorphic loci and average heterozygosity decreased as the cattle were being bred. The results also supported the conclusion that Xuwen and Hainan yellow cattle shouldbe one breed named Leiqiong yellow cattle.