Abstract: In order to characterize the differences in fatty acid composition between varied muscle tissues in Tan sheep and Small Tailed Han sheep,the retention time and concentrations of 31 kinds of fatty acids in biceps femoris,longissimus dorsi muscle and triceps brachii of Tan sheep and Small Tailed Han sheep were determined and statistically compared.The results showed that there was no significant difference in retention time of 31 kinds of fatty acids between varied muscle tissues in both Tan sheep and Small Tailed Han sheep (P>0.05),and the retention time was increased with the elevation of carbon content in fatty acids;compared to the other tested fatty acids,the contents of C16:0,C18:0 and C18:2n6c in varied muscle tissues were all found to be higher in both Tan sheep and Small Tailed Han sheep;extremely significant difference in concentration of C17:0 between varied muscle tissues in Tan sheep and Small Tailed Han sheep was observed (P<0.01).