Abstract:abstract: The study was to investigate the effect of EGF on Bovine preadipocytes which were isolated from bovine perirenal adipose. Effect of doses 10 ng/ml、50 ng/ml、100 ng/ml、200 ng/ml EGF on proliferation and differentiation of preadipocytes were analyzed by MTT colorimetric and incorporation of oil red O. and mRNA expression levels of LPL,PPARγ,A-FABP genes,which were adipocyte differentiated marker genes were determined by semi-quantitative RT-PCR. The preadipocyte proliferation was stimulated significantly by EGF of 10ng/ml (P<0.01). Treated with different doses EGF after induced differentiation could improve adipocyte differentiation and promote the expression of the differentiation marker genes LPL 、PPARγand A-FABP at 8th day .EGF could improve the proliferation and differentiation of bovine preadipocyte.