Objective: To investigate the effect of blood pressure (BP) control level on perinatal outcomes in women with mild-moderate gestational hypertension (GHp). Methods: Totally, 344 women diagnosed initially as mild-moderate GHp who delivered in Peking University Third Hospital from January 2012 to December 2016 were recruited. They were divided into four groups according to the stabilized level of BP during pregnancy. (1) Group A: BP<130/80 mmHg (1 mmHg=0.133 kPa) ; (2) Group B: BP (130-139) / (80-89) mmHg; (3) Group C: BP (140-149) / (90-99) mmHg; (4) Group D: BP (150-159) / (100-109) mmHg. The clinical profile and incidence of severe GHp, pre-eclampsia with proteinuria (PE+Upro), severe pre-eclampsia (sPE), small-for-gestational age (SGA) were compared among the four groups. Student t-test was preformed to normal distributive data and Kruskal-Wallis test was used to non-normally distributed variables. Chi-square test was used in count data. Logistic regression analysis was adopted for multiple-factor analysis. Results: (1) The incidence of severe GHp in group A was lower than group B (P<0.05). The incidences of severe GHp and sPE in the group B was lower than those in group C (P<0.05). While there was no difference in the incidence of PE+Upro and SGA among the four groups (P>0.05). And the incidence of severe GHp in group D had no difference with group A, B, C (P>0.05). (2) In the 48 patients who used medications to control BP, the occurence of severe GHp in those whose initial BP was (140-149) / (90-99) mmHg was lower than those of ≥160/110 mmHg (P<0.05). But the incidence of severe GHp had no significant difference between patients whose initial BP was (140-149) / (90-99) mmHg and patients whose initial BP was (150-159) / (100-109) mmHg (P>0.05). The initial BP level had no impact on the incidence of PE+Upro, sPE and SGA (P>0.05). (3) Multivariate logistic regression analysis showed that the BP level before using medications (OR=3.566, 95%CI: 1.080-11.771, P=0.037) and the BP level maintained (OR=4.787, 95%CI: 1.115-20.551, P=0.035) were independent factor that affected the incidence of severe GHp. Edema (OR=2.651, 95% CI: 1.628-4.316 P=0.000), fetal growth restriction (FGR; OR=1.103, 95% CI: 1.427-5.914, P=0.002) and the onset gestational age of GHp (OR=0.755, 95%CI: 0.578-0.985, P=0.038) were independent factors that affected the incidence of PE+Upro. The tendency of FGR (OR=17.787, 95%CI: 1.833-40.396 P=0.000), history of PE (OR=5.294, 95%CI: 1.086-25.800, P=0.039) and the BP level during pregnancy (OR=2.109, 95%CI: 1.274-3.491, P=0.004) were independent factors affecting the incidence of sPE. FGR tendency was independent factor affecting the incidence of SGA (OR=25.622, 95%CI: 2.596-252.864, P=0.005). Conclusion: A satisfied control of BP is helpful to reduce severe GHp and sPE, but the incidence of SGA does not affected.