Objective To evaluate the application of ultrasound contrast agent SonoVue and pulse subtraction contrast-enhanced ultrasonography (CEUS)in the diagnosis and differential diagnosis of renal tumors.Methods 53 patients with renal tumors or suspected renal tumors were examined by real time pulse subtraction contrast-enhanced ultrasonography with a bolus injection of SonoVue. The whole process of CEUS was recorded by VCD and enhancement beginning time, enhancement disappearing time, and peak intensity value were analyzed. All cases were confirmed by pathology.Results After the administration of SonoVue, The tumor vessels and the tissue of necrosis in the renal tumors foci were clearer after the contrast agent wash in, and the tumor vessels were disordered and tortured. The contour of the renal tumors were clearer during contrast enhancement preiod than in routine ultrasonography. seventeen cases of the thirty-one malignant renal