Objective Investigating the CT features and related prognostic factors of high-grade renal clear cell carcinoma.Methods The data of 141 patients with renal clear cell carcinoma treated by radical nephrectomy in our hospital from November 2012 to April 2017 were analyzed retrospectively.There were 102 males and 39 females.Age from 30 to 86 years old.The tumors were located in the left side in 73 cases and 68 in the right.The tumor size ranged from 1.6 cm to 12.7 cm.50 cases of clinical stage T1a,stage T1b 67 cases,24 cases above T2.All patients had CT examination before operation.According to the postoperative pathological nuclear grade,patients were divided into high grade group (Ⅲ-Ⅳ) and low grade group (grade Ⅰ-Ⅱ),clinical data and CT findings were compared between the two groups (tumor size,capsule,CT,with or without leafs,with or without hemorrhagic necrosis),survival situation after the operation.Result The results of CT examination of 141 cases of this study indicated there were 109 cases of complete capsule,85 cases of tumor showed lobulation,102 cases of tumor showed hemorrhagic necrosis,the average CT value is 10-72 HU,35.4 HU in average;enhanced CT value is 32-308 HU,102.1 HU in average.After pathological examination,the nuclear classification was 66 cases in high grade group and 75 cases in low grade group.The CT examination in thc high grade group and the low grade group showed the number of cases with complete capsule [44 cases (33.3％) vs.65 cases (13.3％)] and plain CT scan value [(38.9 ± 1.1) HU) vs.(32.3 ± 1.1) HU],the difference was statistically of significance (P ＜0.01).The high level of patients in group T1 and group above T2 stage were 46 cases and 20 cases.And the cases of low grade group were 71 cases and 4 cases,there was significant difference between two groups (P ＜ 0.01).The 141 cases were followed up for 2-58 months,with an average of 26.4 months.There was statistical significance difference between the two groups of T1 patients and patients above T2 (P ＜ 0.01).The results of CT examination were compared.There were significant differences in the case of intact capsule and the value of CT scan (P ＜ 0.01).The overall survival rate between the two groups was statistically significant (P ＜ 0.05).Conclusions The CT examination of high-grade renal cell carcinoma shows that most of the capsule is not complete and the CT value of the scan is much higher.The pathological grading of renal cell careinoma indicates the malignancy of tumor cells,which is closely related to prognosis.