Abstract: Objective To explore the trends of incidence and risk factors of hypertensive disorders of pregnancy（HDP） in inpatient deliveries in Ningbo Women and Children Hospital from 2016 to 2020. Methods（1）A retrospective investigation was conducted in 59 474 women who delivered at ≥28 th week of gestation between January 2016 and December 2020 in Ningbo Women and Children Hospital. Clinical data was obtained from the clinical records of the hospital. The trend in the incidence of HDP was analyzed.（2）A total of 4 028 patients with HDP（except chronic hypertension） were included as the case group, 8 056 pregnant women without hypertension who delivered during the same period were selected as the control group. Relative factors were evaluated.（3）Related factors were analyzed year by year from 2016 to 2020 in 59 474 women. Results（1）There were 4 593 HDP cases among 59 474 pregnant women, the incidence rate was 7.7%. The incidence of HDP was statistically significant in different years（χ~2=53.39, P＜0.01）,and showed an overall upward trend（χ~2=6.00, P＜0.01）. The proportions of pre-eclampsia（PE）, severe pre-eclampsia（sPE） in HDP decreased year by year（all P＜0.01）.（2）Multivariate logistic regression analysis showed that age≥35 years, abortion ≥2 times, non-local registered residence, pre-pregnancy body mass index（BMI）≥24 kg/m~2, family history of hypertension, in vitro fertilization and embryo transplantation（IVF-ET）, multiple pregnancy, multiparity, hypothyroidism, hyperthyroidism, gestational diabetes mellitus and intrahepatic cholestasis of pregnancy were related risk factors of HDP, with OR（95%CI） of 1.58（1.41-1.77）, 1.82（1.64-2.03）, 1.21（1.11-1.32）, 1.28（1.16-1.41）, 1.94（1.75-2.16）, 1.25（1.05-1.50）, 2.22（1.86-2.66）, 0.51（0.46-0.56）, 1.14（1.04-1.25）, 1.77（1.07-2.90）, 1.41（1.28-1.56）, 1.44（1.12-1.86）, respectively.（3）The proportion of multiparity and women with abortion ≥ 2 times was the highest in 2017 and has decreased year by year since then. The proportion of age≥35 years, IVF-ET, multiple births and non-local registered residence was highest in 2019, and the proportion of diabetes was highest in 2020, the difference was statistically significant compared with the other 4 years（P＜0.05）. Conclusions The incidence rate of HDP increased from 2016 to 2020, but the incidence of preeclampsia and severe preeclampsia decreased. The incidence of factors related to HDP, such as multiparity, age≥35 years, IVF-ET, multiple births, non-registered residence, abortion ≥ 2 times and gestational diabetes mellitus, was different in different years.