〔Abstract〕 Objective To investigate the characteristics and correlative factors of sialorrhea in patients with primary Parkinson's disease in order to provide individualized management procedures. Methods 59 patients with idiopathic Parkinsonʼs disease were collected. Data of demographic characteristics, clinical features and history of medications were collected. Patients were assessed with a comprehensive serie of scales which include the third part of Unified Parkinson's Disease Rating Scale(UPDRS Ⅲ), modified Hoehn&Yahr Scale(H&Y), levodopa equivalent dose(LED), the freezing of gait questionnaire(FOG-Q), Dynamic Parkinson gait scale(DYPAGS), 39-item Parkinson's Disease Questionnaire(PDQ-39), the Schwab&England Activities of Daily Living Scale(S&E) and the Scales for Outcomes in Parkinson's Disease-Autonomic questionnaire(SCOPA-AUT). The orofacial motor function and swallowing function of patients were evaluated by Radboud Oral Motor Inventory for Parkinson's disease test(ROMP), the water swallowing test and the Nordic Orofacial Test-Screening(NOT-S). Saliva secreted in five minutes from the participants was collected and weighed to assess salivary secretion volume. Results Among 59 patients with Parkinson's disease, 38 patients had sialorrhea, and the incidence of sialorrhea was 64.4%. Severe sialorrhea accounted for 21.1%, while non-severe sialorrhea accounted for 78.9%. The age, scores of Hoehn-Yahr stage, levodopa equivalent dose(LED), SCOPA-AUT scores, PDQ-39 scores, saliva secretion, ROMP-language scores, ROMP-swallowing scores, scores of NOT-S, UPDRS Ⅲ and DYPAGS scores, UPDRS Ⅲ-19 scores in sialorrhea group exceeded those in non-sialorrhea group, while in non-sialorrhea group, S&E scores were much lower. LED and NOT-S scores were independent risk factors of sialorrhea(OR=1.004, 95%CI1.001～1.008,P<0.05;OR=2.379,95%CI1.289～4.392,P<0.05). In addition, sialorrhea severity was positively correlated to age, LED, UPDRS Ⅲ scores, ROMP-language scores, ROMP-swallowing scores, DYPAGS scores, scores of NOT-S, FOG-Q scores, SCOPA-AUT scores, UPDRS Ⅲ-19 scores(r=0.330, 0.327, 0.414, 0.454, 0.416, 0.390, 0.399, 0.477,0.435,0.353,P<0.05).The scores of NOT-S was an independent risk factor of sialorrhea severity(OR= 6.635, 95%CI1.335～32.990,P<0.05). Conclusion Sialorrhea is correlated with many factors, such as age, motor dysfunction severity, equivalent dose of levodopa, severity of autonomic nerve dysfunction, saliva volume, severity of speech and swallowing disturbance, camptocormia, orofacial dysfunction severity. Sialorrhea is closely related to the impaired neuromuscular function of mouth, face, pharynx and larynx. Orofacial motor dysfunction and equivalent dose of levodopa are independent risk factors of sialorrhea.