Objective To study morphological characteristics of placenta in severe pregnancy induced hypertension (SPIH) and its relationship to pregnant outcome. Methods Morphological changes were observed by light microscopy; Blood biochemical analyses were used to predispose pregnant outcome. Results Difference in pathological changes of placental bed between normal term pregnancy (NTP) and SPIH groups was significant: the placental weight, proliferation of cytotrophoblasts, numbers of the placental villi with syncytial knots, thickness of basal lamina, fibrinoid necrosis and deposition of matrix, stromal edema and fibrosis of villi, the vascular numbers of villi, stasis; lack of physiologic changes in decidual spiral arteries. Clinical examination showed that the rate of anemia, thrombocytopenia, blood concentration, hypoproteinemia, ascites, eye ground artery spasm in SPIH were higher in NIT. Conclusions Pathological changes of placenta play important roles in development of SPIH, and the pathological changes are paralleled with the severity of the disease.