Abstract: Genetic structure and character of 57 Chaidamu cashmere goats are studied through simple random sampling, and genetic structure are estimated with PAGE of 9 blood protein（α2 ，Alb，Hb，Alp，PA-3，EsD，Amy，Tf，LAP）, and phylogeny status are investigated. The result indicated that: there was polymorphous blood albumen in 6 loci and the average loci heterozygosity was 0.2773; the average phenotypic heterogeneity degree of coat color and appearance character are 0.4610; using the analyze of the degree of genetic similarity, the relationship between Chaidamu cashmere goat populations and it's parent groups; the coefficient of genetic differentiation between Chaidamu cashmere goats and Liaoning cashmere goats is less than that between Chaidamu cashmere goats and Chaidamu goats on appearance character; the coefficient of genetic differentiation between Chaidamu cashmere goats and Chaidamu goats is less than that between Chaidamu cashmere goats and Liaoning cashmere goats on blood protein marker；the degree of genetic similarity of between Chaidamu cashmere goats and Chaidamu goats, between Chaidamu cashmere goats and Liaoning cashmere goats are 0.8257 and 0.8662, respectively.

Key words: Chaidamu cashmere goat; genetic investigation; the degree of genetic similarity