This proposal is to use bombyx baculovirus system expressing classical swine fever virus E2 antigen and to prepare the E2 subunit vaccine for animal vaccination. The E2 gene was cloned into the genome of baculovirus. The replication rate of recombinant viruses and protein expression levels were determined in Sf9 cells. Each Bombyx infected by recombinant virus could produce approximately 300 ug of E2 antigen. Vaccines were prepared with different amounts of E2 antigen and adjuvants. Vaccine was used to immunize the sows and gilts in a two-dose program to determine the immune and protection efficacy. In addition, two pig farms were selected to perform the field trials including 150 gilts and 30 sows from each farm. Some of the immunized pigs will be purchased and performed virus challenge for determining the protection efficacy.