Objective To investigate the function of moral judgment and its neural mechanism in patients with Parkinson's disease (PD).Methods A total of 40 patients with a confirmed diagnosis of idiopathic PD were enrolled as PD group, and 40 healthy controls matched for demographic data were enrolled as HC group. The Chinese version of the moral dilemma questionnaire developed by Joshua D. Greene was applied for the experiment of situation decision-making in moral dilemmas.Results On personal moral scenarios, the PD group had a significant higher probability of "yes" response (a utilitarian tendency) than the HC group (0.40±0.1 vs. 0.32±0.11; t=2.244, P<0.05). However, on impersonal moral and non-moral scenarios, the probability of "yes" response did not differ significantly between the two groups (P>0.05).Objective PD patients are highly inclined to make utilitarian on personal moral scenarios, which may be related to the abnormality in the frontal lobe-basal ganglia loop.