SNPs of the intron 12 and exon 13 of LAP3 were analyzed by PCR-SSCP, CRS-PCR, PCR-RFLP and sequencing in Chinese Holstein cattles(CH), Luxi Yellow cattles(LY) and Bohai Black cattles(BB). Five SNPs were detected, 24 794(T/G), 24 803(T/C), 24 846(T/C), 24 564(G/A)and 25 415(T/C), among them SNP 24 564(G/A) was new. Three SNPs of 24 794(T/G), 24 803(T/C), 24 846(T/C)were linked completely and detected by PCR-SSCP, but they were not found in Luxi Yellow cattles. The alleles T, T, T, G and T were the dominant alleles in 3 breeds, and the allelic frequencies are T(CH0.579/LY 1/BB 0.722), T(CH 0.579/LY 1/BB 0.722), T(CH 0.579/LY 1/BB 0722), G(CH 0.584/ LY 0.775/BB 0.500) and T (CH 0.596/LY 0.796/BB 0.750). The PIC of the 5 SNPs in these 3 breeds all belong to the midrange polymorphism (0.25<PIC<0.5).