Abstract: 5 ‘UTR of swine fever virus(SFV)was amplified by RT-PCR and cloned into pMD-18 simple T vector to construct a recombinant plasmid pSF，which was used as standard positive template for the fluorescent quantitative PCR(FQ—PCR)to
detect SFV．The pSF was identified by PCR and DNA sequence analysis．The plasmid Was stable after 6 months storage at 一20℃ ．When the plasmids DNA of 1．0×10 9 ， 1．0×10 7 and 1．0×10 7 copies／2 μL were used as template，the largest variation coefiqeient of Ct value was 1．55％．and the FQ—PCR provides a broad linear range from 1×10 7 to 1×10 11 copies of DNA per reaction．The pSF was specific and stable for the FQ-PCR．The method can be used for the clinical diagnosis.

Key words: swine fever virus, fluorescent quantitative PCR(FQ-PCR), recombinant plasmid