Objective The correlation between 24-hour urinary protein quantity and pregnancy outcome in patients with preeclampsia was analyzed retrospectively, which provided clinical basis for diagnosis and treatment of preeclampsia. Methods 222 patients with preeclampsia treated in the First Affiliated Hospital of Nanjing Medical University，Department of Obstetrics，were selected（Diagnosis of gestational age 22~40+6weeks）. According to the results of 24-hour urinary protein quantification, they were divided into mild albuminuria group， moderate albuminuria group，and severe albuminuria group . We compare the clinical manifestations, laboratory indexes and adverse pregnancy outcomes of pregnant women, fetuses and newborns among the three groups. Results 1. Clinical manifestations: In the moderate and severe group, the onset of preeclampsia was significantly earlier than that of the mild group, and the clinical manifestations were more serious. 2.Laboratory indexes: Plasma albumin, serum total cholesterol, lactate dehydrogenase, urea nitrogen and creatinine levels increased significantly in the moderate and severe groups; platelet count decreased significantly in the severe group compared with the mild group, while glutamic oxaloacetic transaminase, triglyceride and D dimer levels increased significantly in the severe group. 3.Maternal adverse pregnancy outcome：The incidence of pleural effusion, HELLP syndrome and peritoneal effusion in moderate and severe group increased significantly. 4.Fetal adverse pregnancy outcome：Iatrogenic preterm birth, fetal growth restriction and neonatal asphyxia increased significantly in moderate and severe groups. 5. ROC curve analysis showed that 24-hour urinary protein quantitative analysis had certain predictive value for HELLP syndrome，pleural effusions and hydroceliac effusion, iatrogenic premature delivery and the occurrence of FGR in pregnant women. Conclusion 24h urine protein quantitative degree is associated with adverse pregnancy outcomes such as HELLP syndrome, pleural and peritoneal effusion, FGR，iatrogenic preterm birth, and can be used as an observation index for the development of preeclampsia.