Objective To explore the correlated factors and clinical features of cognitive impariment in parkinson's disease (PD).Methods A total of 419 patients with PD were collected from Xiangya Hospital of Centre-South University during Mar 1st,2017 to Nov 30th,2017.The cognitive functions of patients were assessed with the Mini-Mental State Examination (MMSE),and the basic information and the motor symptoms of 419 PD patients were selected at the same time.The PD patients were classified into three groups according to the MMSE score:PD with no cognitive impairment (PD-NC),mild cognitive impairment in PD (PD-MCI),and Dementia in PD (PD-D).The data were analyzed by SPSS 20.0.Results There were 156 patients with PD-MCI (37.2％) and 64 patients with PD-D (15.3％).The difference of sex and disease duration among three groups were not statistically significant (P ＞ 0.05).The significant difference was found among PD-D,PD-MCI,and PD-NC groups in age of onset,age,educational attainment,Unified Parkinson's disease Rating Scale (UPDRS)-Ⅱ score,UPDRS-Ⅲ score and Hoehn-Yahr stage (P ＜ 0.05).There were significant differences among three groups in MMSE score and its items (P ＜ 0.01).Logistics regression analysis found that the age of onset,educational attainment,and Hoehn-Yahr stage were the risk factors of cognitive impairment in PD patients (P ＜ 0.05).Conclusions Cognitive impairment is common in PD patients,and it is relevant to the age of onset,educational attainment and the severity of illness of PD patients.