Objective To analyse the relationship between Calpain10 gene UCSNP43 and UCSNP44 poly morphisms and diabetes in familial type 2 diabetes mellitus of Uygur in Xinjiang.Methods Sixty-two Uygur type 2 diabetic families were enrolled.The polymorphisms of Calpain10 gene UCSNP43 and UCSNP44 were measured by SNP-stream of gene chip.Results (1) The heritability of the first degree relative and the second degree relative in Uygur familial type 2 diabetes were 0.578 and 0.032.(2)There was no difference between UCSNP43 and UCSNP44 polymorphisms of the first and second degree relatives in familial type 2 diabetes mellitus.(3)The carriers of USCNP43 AA genotype had higher body mass index and fasting insulin than GG and GA genotypes carriers.Conclu sion With the downgrading of the familial relationship,the heritability of type 2 diabetes mellitus was decreasing. The carriers of UCSNP43 AA genotype might have higher insulin resistance than those with GG and AG genotypes.