Objective:To describe the clinical features and analyze the prognostic factors of blastemaltype Wilms tumor. To explore the clinical risk factors affecting the prognosis of blastoma.Methods:Clinical data of 75 patients admitted to the surgery department of Beijing Children's Hospital from January 2008 to June 2020 who were confirmed to be blastemal-type Wilms tumor by postoperative pathology without preoperative chemotherapy. The patients' general information, clinical characteristics, inspection data, surgical methods and follow-up results were collected. The related factors which influences its prognosis were analyzed. Among the 75 patients, 45 cases (60.0%) were male and 30 cases (40.0%) were female. The diagnosis age was 6-144 m, mean age was 39.1 m. Left side: 38 cases (50.7%), right side: 37 cases (49.3%). The clinical manifestations were abdominal mass in 35 cases (46.7%), hematuria in 24 cases (32.0%), abdominal pain in 7 cases (9.3%) and physical examination in 9 cases (12.0%). There were Stage Ⅰ 30 cases, Stage Ⅱ 28 cases, Stage Ⅲ 15 cases, Stage Ⅳ 2 cases. There were preoperative tumor rupture in 5 cases, intraoperative tumor rupture in 2 cases. Clinical stage Ⅰ and Ⅱ were classified as early, while stage Ⅲ, Ⅳ were classified as late. According to COG protocol, stage Ⅰ and Ⅱ patients received EE4A, stage Ⅲ and Ⅳ patients received DD4A protocol and radiotherapy. The number of lymph nodes sampled during operation was more than 7 in 10 patients.Results:7 cases were tested for 1p16q. One case(stage Ⅱ) was absent at 1p/16q LOH, and chemotherapy was upgraded from EE4A to DD4A. After the recurrence of 1 case in clinical stage Ⅰ, the 1p/16q heterozygotic deletion test was performed, which was changed to M regimen chemotherapy. Only 1p lost in one case, and 1p/16q was negative in 4 cases, so the original chemotherapy regimen was maintained. A total of 67 patients were recruited to the study. The median follow-up time was 57 months. The 5-year relapse-free survival(RFS) rate was74.7%, and the 5-year overall survival(OS) rate was 88.0%. Cox multivariate regression analysis showed that: advanced clinical stage ( HR=4.9, 95% CI 1.2-19.6, P=0.025), tumor volume ( HR=1.7, 95% CI 0.4-6.9, P=0.048), and tumor rupture ( HR=20.1, 95% CI 4.7-85.5, P<0.001) were independent risk factors for prognosis of blastoma. Gender, age, side profile, clinical manifestations, tumor embolism, and number of lymph nodes sampled had no significant influence on the survival rate of blastoma ( P>0.05). Conclusion:Advanced stage (Ⅲ-Ⅳ), tumor volume≥1 000 ml, tumor weight and tumor rupture were independent risk factors for relapse. Insufficient lymph node sampling and incomplete 1p16q, may be the reasons for the increased risk of local recurrence in low-stage patients due to the underestimated risk classification and insufficient treatment intensity.