Abstract: Objective: To evaluate the killing effect of mitomycin loaded immunomagnetic albumin microspheres（MMC-IMAMS） against human colorectal cancer in vitro and in vivo.Methods: using MTT assay to evaluate the specific cytotoxic effects on target LoVo cells of MMC-IMAMS,mitomycin loaded magnetic albumin microspheres（MMC-MAMS）,and mitomycin（MMC） in vitro.Then MMC-IMAMS,MMC-MAMS,and MMC were injected into nude mices bearing human colorectal carcinoma respectively to study the inhibitory activity in vivo.Results: The cytotoxic effects of MMC-IMAMS group were higher than MMC-MAMS group and MMC group.The inhibitory rate of MMC-IMAMS group on the growth of colorectal cancer xenografts was significantly higher than that of MMC-MAMS group or MMC group.MMC-IMAMS were safe and could deposit at the target area for quite a long time under the influence of magnetic field.Conclusion: The MMC-IMAMS are safe and have higher targeting and anticancer ability than MMC-MAMS in vitro and vivo.