Objective To investigate the value of contrast enhanced ultrasonography in evaluating cystic renal mass. Methods According to the imaging diagnosing standard, 29 cystic renal mass lesions were studied with contrast enhanced ultrasonography(CEUS), unenhanced ultrasonography (US), contrast enhanced CT(CECT) and then correlated their results with final histopathological results. The data were tested by receiver operating characteristic(ROC) curve. Results The area under ROC curve of CEUS and US was 0. 721, 0. 997, respectively. There was significant difference between the 2 groups (P=0. 003). The area under ROC curve of CEUS and CECT was 0. 997, 0. 997,respectively. There was no significant difference between the 2 groups (P= 1. 000). Conclusions CEUS is better than US and similar to CECT in evaluating cystic renal mass. CEUS with the Bosniak classification is useful for evaluating cystic renal mass.