Abstract: To investigate the molecular characteristics including gene variation and tissue expression of goat FGF5 gene and effect of its variation on cashmere traits in goat, PCR-SSCP combined with sequencing were used to detect the polymorphism of exon 1 of FGF5 gene in Longdong Cashmere goats, Chaidamu Cashmere goats and Zhongwei goats, and analyze the effect of FGF5 gene variation on cashmere traits were analyzed. RT-qPCR technique was used to study the expression of FGF5 gene in tissues of Liaoning Cashmere goats and Longdong Cashmere goats. The result showed that there was a synonymous SNP site c.272 C＞T in the exon 1 of goat FGF5 gene, and there were three genotypes, named MM, MN, and NN, respectively. NN was rare and only detected in Longdong Cashmere goats. All the dominant genotypes and alleles of the three goat breeds were MM and M. c.272 C＞T was in Hardy-Weinberg equilibrium among the three goat breeds, and all of them showed low polymorphism. The association analysis between c.272 C＞T and cashmere traits of Longdong Cashmere goats showed that this SNP had a significant effect on cashmere fiber diameters. The cashmere fiber diameter of individuals with N was significantly lower than that of individuals without N（P＜0.05）; The cashmere fiber diameter of individuals with MN genotype was significantly lower than that of individuals with MM genotype（P＜0.05）. The FGF5 gene was expressed in the heart, liver, spleen, lung, kidney, skeletal muscle and skin of Liaoning Cashmere goats and Longdong Cashmere goats; the expression in the heart, spleen, lung and kidney and skin of Longdong Cashmere goats was significantly higher than that of Liaoning Cashmere goats. These results suggested that goat FGF5 gene could be used as a candidate gene for breeding programs based on improving fibre diameter.