Abstract: Objective To analyze the effect of contrast-enhanced ultrasonography, enhanced CT and combined examination in the qualitative differential diagnosis of renal space occupying lesions. Methods Total 126 cases of renal space occupying lesions whom were treated in Ninghai First Hospital Medicare and Health Group from February 2017 to February 2020 were studied. All patients were examined by contrast-enhanced ultrasonography and contrast-enhanced CT respectively. The sensitivity, specificity and accuracy of contrast-enhanced ultrasonography, contrast-enhanced CT and combined examination in the differential diagnosis of benign and malignant renal space occupying lesions with different pathological types and different lesions sizes were compared. Results In the differential diagnosis of different pathological types of renal space occupying lesions, the sensitivity(96.47%) and accuracy(93.65%) of combined examination were significantly higher than those of contrast-enhanced CT(78.82% and 74.60%)(all P<0.017), while there was no significant difference in sensitivity(88.24% vs. 84.92%) and accuracy(84.92% vs. 74.60%) between contrast-enhanced ultrasonography, enhanced CT alone(P>0.017). In the differential diagnosis of benign and malignant renal lesions with a diameter ≥ 3 cm, there was no significant difference in sensitivity, specificity and accuracy of the three examinations(all P>0.017). In the differential diagnosis of benign and malignant renal lesions with a diameter<3 cm, the sensitivity(94.34%) and accuracy(91.78%) of combined examination were significantly higher than those of contrast-enhanced CT alone(67.92% and 64.86%)(all P<0.017), and the sensitivity(88.68%) and accuracy and(85.14%) of contrast-enhanced ultrasound were significantly higher than those of contrast-enhanced CT(67.92% and 64.86%)(all P<0.017). Conclusion Contrast-enhanced ultrasound and contrast-enhanced CT have higher qualitative diagnostic value for renal space occupying lesions. Contrast-enhanced ultrasound is slightly better than contrast-enhanced CT in the qualitative diagnosis of small renal space occupying lesions. The combined diagnosis can improve the differential diagnosis efficiency of benign and malignant renal space occupying lesions.