Abstract: Splenocytes from BALB/c mice immunized with soluble antigen of Toxoplasma gondii tachyzoites were fused with the NS-1 mouse myeloma cells. 11 hybridomas secreting antibodies against T.gondii were obtained,the positive rate being 5.1%.Among the 11 hybridomas, one strong antibody secreting strain was selected, and through cloning 5 times, a hybridoma cell line was developed, secreting steadily the monoclonal antibody (McAb) with specificity for T. gondii. ELISA test showed that the titer of the McAb in the ascites fluid from the BALB/c mice injected with the hybridoma cells was as high as 1:51,200. It was confirmed that the McAb belonged to IgG2a.