Abstract: Objective To study the mechanism of TP inducing apoptosis of colon cancer SW-480 cell.Methods The influce of TP on proliferation of SW-480 cell in vitro was detected with MTT method;The ultrastructure of cell was observed with electron microscopy.Results Compared with control group,the proliferation of SW-480 cell lines in experimental group was obviously inhibited,spindle-shaped and round cells loosely distributed,some round cells increased within the particles after TP treatment.Cell sizes,nuclear atypia,and a collapse of apoptosis,nuclear biased towards one side,the cytoplasm is rich in free ribosome,mitochondria thick,the cell apoptotic body were seen under electron microscope.Conclusion TP can inhibit the growth of SW-480 cell and induce cell apoptosis in vitro.