Abstract: Abstract:Amplification of mammalian male-determining gene SRY with polymerase chain reaction(PCR) to identify the gender of embryos, has been widely used in animal husbandry, optimizing the technical route to shorten the time has a very important significance in the latter part of the experiment. In this study, we designed and synthesized two pairs of primers according to pig SRY gene and GAPDH gene (internal standard) to rapidly identify gender of the early pig embryor by Two-temperature PCR reaction, results showed that:the 404bp of the GAPDH gene fragment can be amplified with the sow gene, while the 309 bp of the SRY gene fragment and 404 bp of the GAPDH gene fragmen can be simultaneously amplified with the boar gene. The positive rate was 100%, identification time is shorten 2 hours than the normal methords. This indicates that this detection method is fast and accurate, it provides a reliable technical assurance for sex identification of fetal fibroblast cell lines in the study of transgenic animals.