Abstract: For searching the differences of amino acids content between the different breeds of sheep or the different strains of the same breed,the content of 17 amino acids of wool in 4 breeds,including Hetian sheep (Pure plain Hetian,Pure mountain Hetian and New Hetian strains),Karakul sheep (Silkworm,girdle-type and rib-type three flower-types),Duolang sheep and Chinese Merino was determined by high performance liquid chromatography (HPLC). The results showed that the total amino acid content of wool from Hetian sheep was higher than that of Duolang sheep,and the difference was statistically significant(P＜0.05). The differences in amino acids content were not statistically significant between the other breeds(P＞0.05). Those amino acids in Duolang sheep such as Asp,Ser,Glu,Arg,Thr,Ala,Pro,Val,Lys,Ile,Leu,Phe were lower than that of the other breeds. The content of Cys in Karakul sheep was higher than that of the other breeds,but Ser,Gly,Thr,Pro,Tyr were lower than that of the other breeds. The ratio of α-helix promoting/α-helix inhibiting amino acids in the wool,Chinese Merino was 0.90,while Karakul sheep was 0.79,Hetian sheep was 0.77 and Duolang sheep was 0.75.The results showed that, total amino acids of Hetian sheep wool was higher than that of other species, the helix ratio of Chinese Merino wool was higher than that of other species,the cystines of Karakul and Hetian sheep wool were higher than that of other species.

Key words: Hetian sheep; Karakul sheep; Duolang sheep; Chinese Merino; wool; amino acids content