Abstract: The experiment was undertaken to comparatively study muscle chemical composition of crossbred male and female lambs of Poll Dorset × Small Tail Han Sheep. Five male and female lambs，respectively chosen from the flocks raised in intensive production system，were slaughtered at age of 7-month-old. Longissimus dorsi (LD) was sampled and muscle chemical composition was determined. The results showed that there was no significant difference in the contents of dry matter，crude protein，crude fat，ash，calcium，and phosphorus，various amino acids，total essential amino acids，total non-essential amino acids，and total amino acids，fatty acids，total unsaturated fatty acids，Mg，Zn，Cu，and Mn in LD between male and female lambs(P>0.05). The content of linoleic acid in LD of male lambs，however，was increased by 20.3%(P<0.05) and cholesterol decreased by 32% (P<0.05) compared with female lambs. Iron in LD of female lambs was higher about 26% than that of males. The present study indicated that the nutritional value of Longissimus dorsi was the same between male and female lambs slaughtered at age of 7-month-old.

Key words: intensive production system; lamb; sex; muscle; chemical composition