Abstract: The primers were designed and synthesized according to the sequences of S gene of transmissible gastroenteritis virus （TGEV）, and then reaction requirements were optimized to develop a SYBR Green Ⅰ fluorescence quantitative RT-PCR assay. Meanwhile, 12 field samples were detected and the results were compared with that of routine RT-PCR. It was showed that the fluorescence quantitative RT-PCR assay could detect 43.07 copies/μL of plasmid DNA and its specificity and reproducibility were very good, while the sensitivity of the routine RT-PCR was 4.307×10³ copies/μL.The results of field test also showed that its sensitivity was higher than that of routine RT-PCR. The SYBR Green Ⅰ fluorescent quantitative RT-PCR assay for detecting S gene of TGEV was developed for the basis of early， rapid detection and quantitative analysis of the infection intensity of TGEV in this experiment.

Key words: transmissible gastroenteritis virus of swine; S gene; SYBR-Green Ⅰ; fluorescence quantitative RT-PCR; standard curve