To distinguish JXA1-R vaccine strain and NADC30-like HNhx strain of porcine reproductive and respiratory syndrome virus(PRRSV),TaqMan real-time quantitative PCR and SYBR Green Ⅰ realtime quantitative PCR were established by using specific primers based on the difference of the regions of Nsp2 genes between HNhx and JXA1-R.The results indicated that the standard products had a good linear relationship in the range of 10³—10⁸ copies/μL,and the R² of the standard curves were over 0.990 in two methods.The detection limit of the TaqMan-based fluorescent quantitative PCR was 10⁴copies/μL(JXA1-R) and 10³copies/μL(HNhx),respectively.The detection limit of SYBR Green Ⅰ fluorescent quantitative PCR was 100 copies/μL.The reproducibility of intra-and inter-assay displayed that the coefficient of variations was less than 1.5%,the repeatability was good.In conclusion,the method for differentiation of HNhx and JXA1-R was successfully established in this study, which exhibited good stability and high specificity, and provided a new technical support for the differential detection of PRRSV.