Abstract: Objective To evaluate the clinical features and epidemiological trend of diabetes ketosis (DK) in patients admitted to West China Hospital. Methods We reviewed medical records of diabetic patients with DK who were admitted to West China Hospital from 1997 to 2005. Their clinical and laboratory data were analysed with SAS 9.0. Results From 1997 to 2005, the proportion of diabetic patients with DK increased by 0.12% annually. The proportion of provoked DK patients (who had a clinically evident precipitating factor) in those with DK remained stable; whereas the proportion of T1D patients in those with DK declined by 2.00% annually and the proportion of ketosis prone obesity diabetes (KPD) in those with DK increased by 2.27% annually. The KPD patients displayed a striking male predominance (2.31∶1, male∶female) and were diagnosed at an older age compared with those with T1D 〔(46.3±12.9) yr. vs. (28.9±14.7) yr.〕. The KPD patients were more likely to have a strong family history of diabetes and a better β-cell function reserve, and be accompanied with dyslipidemia (52.7%), hypertension (23.3%), fatty liver (10.1%) and hyperuricemia/gout (8.5%) compared with those with T1D. Conclusion In recent years the proportion of KPD patients in the hospitalized DK patients is increasing. With different characteristics compared with typical T1D, KPD might belong to a subgroup of T2D.