Abstract: Here we report the construction of sheep PrP gene standard plasmid DNA and curve using real-time RT-PCR. Total RNA was extracted from each sample and the fragments of target gene were amplified by RT-PCR. The plasmid was constructed for calibrating unknown samples. In this study, the constructed plasmid containing only the target gene was used to construct a calibration curve. The absolute standard curve method was shown to be of high linearity, sensitivity and reproducibility. The purpose of this study is to investigate the quantification of PrP mRNA expression for knowing the scrapie pathogenesis and providing powerful tool for further studies on prion diseases pathogenesis.