Non-motor symptoms (NMS) are important preclinical features of Parkinson's disease (PD) and have become the leading cause of poor quality of life with disease progression. There are little data on how antiparkinsonian medications influence the NMS in PD at early stage. In this study, we explored the distribution of NMS in treated and untreated PD and investigated the association between NMS and antiparkinsonian medications in Chinese patients with early PD. Subjects were enrolled from a Chinese PD patient cohort based on 2 clinical trials. Face-to-face interviews and evaluations were performed for clinical information. NMS were compared in patients with or without antiparkinsonian treatment, and between subgroups of dopaminergic medications. Eight hundred and sixteen PD patients were enrolled in this study, of whom 428 were newly diagnosed PD. Only 5 in 646 patients who completed all these NMS measurements (0.6%) were free of NMS. PD patients with antiparkinsonian medications had a significantly higher frequency of poor sleep (p = 0.001), depression (p = 0.0001) and constipation (p = 0.0001) after adjusted gender, onset age, duration, and Hoehn & Yahr stage. Moreover, patients treated by levodopa plus dopamine agonist had a higher percentage of bad sleepers (adjusted p = 0.040), and correlation analysis revealed that Levodopa Equivalent Dose (LED) was associated with constipation (coefficient 0.146, p = 0.005). These findings suggest that although NMS exist in the prodromal stage of PD, antiparkinsonian treatment is associated with increased frequency of some NMS, which may challenge the management for PD.