Abstract: Genetic variations of KAP13.1 gene have been studied in 816 animals of Xinjiang goat breeds in China. The genotypes and allele frequencies of KAP13.1 gene were detected by PCR-RFLP techniquies. At the same time, parts of our samples were sequenced and analyzed with cashmere production traits data. The results showed that TT genotype significantly higher of body weight after combed trait than GT genotype (p<0.05) and down cashmere thickness trait showed genotype GT with significant higher than GG (p<0.05) in Nanjiang cashmere goat. In Xinjiang goat, the fiber diameter showed significant differences (p<0.05) among the age two, three and four years old. The fiber diameter trait in one year old cashmere goat had significant differences (p<0.05) compared with two, three and four years old. The frequencies of the KAP13.1-T allele in Xinjiang goat (n = 220), Nanjiang cashmere goat (n = 310) and Bogeda cashmere goat breeds (n = 286) were 0.996, 0.568 and 0.969, respectively. The χ2-test showed that the genotype distributions in these three cashmere goat breeds were not in agreement with Hardy-Weinberg equilibrium. According to the classification of PIC, Nanjiang cashmere goat was more polymorphic at this locus. The mutation in our animals at KAP13.1 locus was recorded for the first time. In conclusion, The results possibly revealed that the polymorphism existed in the three Xinjiang local goat breed and a missense mutation was possibly caused by variations in the number of the decapeptide repeat structures. Further analysis of results leads us to believe that the polymorphism of KAP13.1 gene might be relevant to fiber diameter and other cashmere traits. Thus, molecular genetic study of KAP13.1 gene represented valuable results for genetic conservation purposes and economic production of cashmere traits.