〔Abstract〕 To explore the breeding and genotype analysis of Lanosterol synthase(LSS) gene knockout mice. The introduced heterozygous knockout mice were reared and bred, the tails of progeny mice around 2 weeks old were cut, their genomic DNA was extracted, the target gene fragments were amplified by PCR reaction and identified by agarose gel electrophoresis Genotype of mice; Western blot analysis was used to analyze and compare LSS protein expression in livers and skin tissues of heterozygous and wild-type mice. A batch of LSS knockout mice were successfully bred, and their progeny mice were identified by PCR with two genotypes: wild type(LSS+/+, Wt) and heterozygous(LSS+/-), which did not appear Homozygous knockout mice; Western blot results showed that compared with wild-type mice, LSS gene knockout heterozygous mice expressed less LSS protein in liver and skin tissues; the viability of heterozygous knockout mice was weaker than that of wild-type mice. Successfully obtaining LSS gene knockout mice, PCR identification of mouse genotypes has the advantages of fast, simple and stable, which lays the foundation for further study of the biological function of LSS.