Aim To Prepare anti-hCD154 monoclonal antibody and analysis its immunological properties.Methods The GST-hCD154 fusion protein was used as antigen to immunize BALB/c mouse. B cell was fused with myeloma cell SP2/0 to produce hybridoma cell line that can secrete anti-hCD154 antibody. The hybridoma cells were identified by using ELISA, Western-blot and FACS method. Results (1) ELISA result demonstrated that culture supernatants of three hybridoma cells(6c5, 1B₆, and5c3) can react with GST-hCD154 ,but not react with GST.(2) Western-blot show that three monoclonal antibodies could bound to a protein band with molecular weight of 56 kDa (GST-hCD154) ,but could not bound to a protein band with molecular weight of 26 kDa (GST). (3) FACS show that McAb 6c5 can bound to peripheral blood T cell activated. Conclusion 6c5 cell is a specific McAb against human CD154 molecules expressed on actived human T cells. Preparation of anti-hCD154 monoclonal antibody be used to study the inhibitory function of atherosclerosis progression.