Abstract: The F gene deletants were constructed and expressed in prokaryotic cell in order to clarify the fusion mechanism between the envelope of peste des petits ruminants virus（PPRV）and the host cells. Considering the key roles in the fusion process，HR1 and HR2，the two conserved fragments of F gene，were cloned into prokaryotic expression vector pET-30a，respectively. The recombinant plasmid pET30a-HR1 and pET30a-HR2 with the confirmed correct sequences were transformed into Escherichia coli BL21（DE3）and expressed by the induction of IPTG. The fusion proteins were largely expressed under the optimal condition and purified using the nickel agarose gel. The results showed that the relative molecular masses of the fusion proteins expressed in form of soluble protein were consistent with the expectation，and the purities of the expressed proteins were over 90%. The fusion proteins reacted with both anti-His tag antibody and anti-PPRV Nigeria75/1 positive serum，indicating that the fusion protein had reactionogenicity.

Key words: F gene deletant, prokaryotic expression, peste des petits ruminants virus