【Objective】To explore the diagnostic value of urine ErbB3 protein in clear cell renal cell carcinoma. 【Methods】We collected 31 urine samples of clear cell renal cell carcinoma patients who received operations in the Urology Department of the First Affiliated Hospital of Sun Yat-Sen University from April 2，2016 to August 31，2016. Meanwhile we collected 50 urine samples of normal people as control. We tested the expression of urine ErbB3 protein in experimen? tal group and control group，and analyzed the differences between the two groups. Then we established the ROC curve of which diagnosing clear cell renal carcinoma by urine ErbB3 protein. Also，we analyzed the relation between ErbB3 pro? tein in urine and the patients’BMI，preoperative creatinine，tumor diameter and underlying diseases such as hyperten? sion and hyperglycemia.【Results】① The expression of urine ErbB3 protein in clear cell renal cell carcinoma group was significantly lower than normal group（P<0.001）. ② When diagnosing clear cell renal carcinoma by ErbB3 protein，the AUC of ROC was 0.802（P<0.001）. When setting the cutoff as 13.98 pg/mL，the max Youden index was 0.525，the sensitivity was 0.645 and the specificity was 0.880. The Kappa value of diagnostic test was 0.542（P<0.001）. ③ Therewas no correlation between the ErbB3 content and patients’BMI，tumor diameter or preoperative creatinine by correlation analysis. Also，there was no correlation between the urine ErbB3 protein content and blood pressure or blood glucose. 【Conclusion】The urine ErbB3 protein of clear cell renal cell carcinoma was significantly lower than normal people，and it is meaningful for applying urine ErbB3 protein to early diagnosis of clear cell renal cell carcinoma.