To investigate the change of serum endothelin-1 (ET-1), nitric oxide (NO), and cystatin C (CysC) of pregnant women with different degrees of pregnancyinduced hypertension (PIH), and to study their correlated with the renal function indexes of these women. Methods: A total of 80 pregnant women with PIH were selected and were divided into group A (30 women with hypertensive disorder complicating pregnancy), group B (26 women with mild preeclampsia), and group C (24 women with severe preeclampsia/eclampsia) according to the severity of their PIH from January 2019 to October 2020. These women were also divided into group D (46 women with normal renal function) and group E (34 women with impaired renal function) according to whether accompanied with renal impairment or not. In addition, 60 healthy pregnant women who underwent regular antenatal examination were selected in control group. The levels of serum ET-1, NO, and CysC of the women in these groups were detected, and the correlation of which with the severity of PIH or renal impairment of the women was analyzed. Results: The serum ET-1 and CysC levels of the women in group A, group B, and group C had increased gradually, and which of the women in group A, group B, and group C were significantly higher than those of the women in the control group. The serum NO level of the women in group A, group B, and group C had decreased gradually, and which of the women in group A, group B, and group C was significantly lower than that of the women in the control group. The serum ET-1, CysC, and creatinine (Cr) levels of the women in group E were significantly higher than those of the women in group D, and the NO level of the women in group E was significantly lower than that of the women in group D (all P< 0.05). The serum ET-1 and CysC levels of the women with PIH were positively correlated with their Cr level, and the NO level of the women with PIH was negatively correlated with their Cr level (all P<0.05). Conclusion: The serum ET-1, NO, and CysC levels of the women with PIH are related to the severity of their PIH and renal impairment.