Objective To prepare the monoclonal antibody against human perforin(HP). Methods Recombi- nant eukaryotic expression plasmid pCDM8-HP was extracted and purified, and the BALB/C mice were immunized with the plasmid. The hybridomas producing anti-HP McAbs were established by using hybridoma technique, then the specificity of the McAbs was identified by using immunocytochemical technique and Western blot. Results Three hy- bridoma cell lines secreting McAbs against human perforin were established, and the three McAbe showed positive only with LAK cells containing human perforin protein, and showed negative with inactive human peripheral blood lymphocytes (PBLs). The subclasses of the three McAbs were determined as IgG2bK. Western blot results showed that the three McAbs recognized a specific band of LAK cell lysateds with molecular weight of 70.0Kd. Conclusion The three hybridoma cell lines secreting McAbs against human perforin were established and the secreted McAbs were specific. Objective To prepare the monoclonal antibody against human perforin (HP). Methods Recombi- nant eukaryotic expression plasmid pCDM8-HP was extracted and purified, and the BALB / C mice were immunized with the plasmid. The hybridomas producing anti-HP McAbs were established by using hybridoma technique, then the specificity of the McAbs was identified by using immunocytochemical technique and Western blot. Results Three hy- bridoma cell lines secreting McAbs against human perforin were established, and the three McAbs showed positive only with LAK cells containing human perforin protein, and showed negative with inactive human peripheral blood lymphocytes (PBLs). The results of the three McAbs were determined as IgG2bK. Western blot results showed the three McAbs recognized a specific band of LAK cell lysateds with molecular weight of 70.0Kd. Conclusion The three hybridoma cell lines secreting McAbs against human perforin were established and the secreted McAbs were specific.