ObjectiveTo establish a mouse mastocytoma P815 model and make a preliminary study on the induction of specific CTL responses in this model. MethodsWe screened a monoclone P815 cell line by limiting dilution assay (LDA),and detected whether the cell line expresses gene P1A with RT PCR and DNA sequencing. Then DBA/2 mice were immunized with the living P815 cells and monitored the specific CTL responses by 51 Cr release assay. ResultsWe have selected a cell line P815 F3 and identified the expression of P1A gene in this cell line;after immunization with the living P815 F3 cells,the anti P815AB specific CTL responses could be detected in 3/6 mice.ConclusionAfter establishing the P815 tumor model,we make a preliminary study on the induction of specific CTL responses in vivo ,proving that immunization with the living P815 cells could initiate anti P815AB specific CTL responses in about 50% mice.