[en] Objective: The aim of this study is to explore the risk factor caused by renal space-occupying. Materials and Methods: From Jan 2000 to Mar 2003,75 patients (41 male, 34 female) with renal space-occupying, age from 14 to 71 years, who underwent radical nephrectomy were studied in our hospital. 1. All patients were performed by Tc99m-DTPA dynamic renography 2 days before operation:then GFR (GATES) and blood pressure of pre-operation were measured. 2. All patients were divided into two groups according to the pathology of post-operation:Group A (GA)is renal cell carcinoma and group B (GB)is other renal space-occupying. We compared the incidence rate of hypertension between two groups. 3. All cases were divided into two groups based on the GFR of the contralateral kindey without space-occupying, The first group(group I) is GFR≥50 ml/min and the second(group II) is GFR<50 ml/min. Results: 1. The average GFR of the contralateral kindey without space-occupying is 46.48± 10.09 ml/min(37.2-85.6 ml/min). 2. The incidence rate of hypertension of renal cell carcinoma is 17.4% (GA) and 20.7% in other renal space-occupying(GB) respectively.There is no significant difference between two groups(P>0.05). 3. There is no hypertension case in the group I. 14 hypertension cases are in group II. The incidence rate of hypertension in group II is 25%. There is a significant difference between two groups(P<0.05). Conclusion: GFR<50 ml/min in the contralateral kindey without space-occupying is the risk factor of hypertension in patients with space-occupying. (authors)