Objective：To compare the clinical characteristics，diagnosis and treatment between incidental renal carcinoma and non-in－cidental renal carcinoma. Methods：Clinical data of 246 hospitalized patients with renal carcinoma in our hospital from 2006 to 2012 were retrospectively analyzed. The 246 patients were divided into incidental renal carcinoma group（n=140） and non-incidental renal carcinoma group（n=106） and were evaluated according to the gender，tumor location，tumor size，pathological types，clinical stagings，path and range of operation. Results：Renal lesions of non-incidental renal carcinoma patients are usually firstly diagnosed by B-ul－trasound. Differences between incidental renal carcinoma and non-incidental renal carcinoma in aspects of sex，position of tumor and pathological types were not significant. The age of incidental renal carcinoma patients was older，the size was smaller，the clinical stage was lower compared with those of non-incidental renal carcinoma patients，with statistically significances（P<0.05）. Conclusions：Ul－trasonography and CT are the main imaging examinations to detect incidental renal carcinoma.More chances of nephron sparing surgery have been provided to incidental renal carcinoma patients，which helps to improve the post-operative quality of life and long-term survival.