Abstract: Crossbred experiment was conducted by using Dorper sheep(paternal form),German Mutton Merino sheep(paternal form)and Ujumuqin sheep(maternal form)with same age and rearing condition to analyze the growth and slaughter performance of the crossbred F1 generation of lamb(Dorper×Ujumuqin,Merino×Ujumuqin and Ujumuqin×Ujumuqin).The results showed that the born weight,1-month age weight,3-month age weight and 6-month age weight of the F1 lamb of Dorper×Ujumuqin and Merino×Ujumuqin were significantly higher than Ujumuqin×Ujumuqin F1 lamb(P<0.05);while the born weight,1-month age weight and 3-month age weight of the F1 lamb of Dorper×Ujumuqin were significantly higher than Merino×Ujumuqin F1 lamb(P<0.05),no significant difference in 6-month age weight between Dorper×Ujumuqin and Merino×Ujumuqin was observed;the pre-slaughter empty body weight,carcass weight and pure meat weight of F1 hybrids of Dorper×Ujumuqin and Merino×Ujumuqin were significantly higher than F1 lamb of Ujumuqin×Ujumuqin(P<0.05);there were no significant differences in slaughtering percentage and pure meat percentage among three crossbred combinations.The combined data suggest that the growth and slaughter performance of F1 generations of hybrid lamb can be significantly improved,and the Dorper sheep and German Mutton Merino sheep can be used as paternal form to improve the local breeds of sheep in Xilin Gol League of Inner Mongolia.Furthermore,this breed improvement strategy also provides an important basis for the high-quality development of local animal husbandry.