Objective: To evaluate morphological changes of cellular and tissues of uterine endometrial and placenta after administration of phytohemagglutinin (PHA) from red kidney bean for termination of middle-late pregnancy in mice. Methods: Mice with 14 days gestation age (middle-late period of pregnancy) were injected PHA from red kidney bean to one side of uterine by nonsurgical method through vagina. PBS were used in control group. Placenta and uterine were collected at 2, 5, 8 hours after administration PHA or PBS (control group). Trypan blue and methyl green-pyronin were prepared for staining and observing. The endometrial and placenta tissue were collected and prepared for microscopic and TUNEL analysis for apoptosis, DNA extraction and electrophoresis, homogenating and preparing for PGF2α analysis. SPSS 11.5 software was used for data analysis. Results: Compared with the control group, PHA treatment induced blood congestion and necrosis in placenta and apoptosis as well as dye by trypan blue at the edge of the placenta. The result of methyl green-pyronin and DNA electrophoresis showed necrosis and apoptosis of placenta. The change of the level of 8-iso-PGF2α was no significant in placenta homogenate, while obvious in uterus homogenate. Conclusion: Administration of PHA could induce the placenta to apoptosis and necrosis, which may be the mechanism  of PHA in termination of pregnancy.