Abstract: This experiment was conducted to explore the expression and function of cyclin dependent kinase 5 in alpaca skin. The whole testes were obtained from adult alpacas of white and brown hair colors. The localization of CDK5 in alpaca skin was examined by immunohistochemistry, and comparative mRNA expression quantity of CDK5 in alpaca skin of different coat colors was analyzed by QRTPCR. The results showed that the positive signals were found in hair bulb and outer rootsheath of hair follicles in alpacas, the difference of expression was significant between the white and brown alpaca′s based on the average optical density(P<0.05). The result of QRTPCR showed that the comparative mRNA expression quantity of CDK5 in brown alpacas was 1.624 5 times than white ones. The findings showed that CDK5 may involved in the regulation of hair color formation.