Background and pnrpose: Renal cell carcinoma (RCC) was the most lethal urological tumor. Not much data mentioned the correlation between the clinical significance of renal capsular involvement status and the clinical symptoms or stage. Our study was aimed to reveal the clinical significance of renal capsular involvement status in RCC. Methods: We retrospectively analyzed 101 consecutive Chinese RCC patients treated in 2006. All the patients received nephrectomy in our hospital. We documented and compared their clinical symptoms, histopathological findings and clinical stages according to 2002 TNM staging systems. Results: Fifty-five patients had no symptoms at diagnosis, 24 complained of lumbago, 18 endured gross or microscopic hematouria, and 14 had generalized symptoms such as cachexia and/or metastatic symptoms. After pathologic analysis, there were 68 cases confirmed as stage T_1, 9 as stage T_2, and the other 24 cases over stage T_2, of which 19 were stage N_(1-2) or M_1. None of those who complained of lumbago had capsular penetration;all 11 patients with capsular penetration did not complain of lumbago. For those with lesion >4 cm, 29% (10/35) with no complaint of lumbago had capsular penetration. Bad general performance status indicated capsular penetration (Pearson Chi-Square, P<0.001). Capsular invasion was found 40% (40/101) in all, and 71% (17/24) in tumor >7 cm;capsular penetration was 11% in all, and 28% (11/40) in cases of capsular invasion. For cancer confined within kidney, lymph nodes or visceral metastases occurred occasionally regardless of capsular invasion (4/29 vs 9/61, Pearson Chi-Square,P>0.05);for cancer with capsular invasion, the incidence of lymph nodes or visceral metastases decreased without further penetration (6/11 vs 4/29, Pearson Chi-Square, P<0.01). Conclusion: Complaint of lumbago indicates organ confined disease in RCC. For large lesions in kidney, absence of lumbago predict renal capsular penetration. Renal capsular involvement status correlates well with clinical symptoms and TNM stages. Capsular invasion is often seen, especially for large lesions, but further penetration is rare. Capsular invasion without penetration does not increase the risk of systematic metastases, and renal capsular has a protective role against the spread of cancer.