To evaluate the association of white matter hyperintensity (WMH) with dopamine transporter (DAT) availability in patients with early to mid-stage parkinson's disease (PD) and multiple system atrophy (MSA). The clinical and imaging data of 55 patients were collected, including 38 PD and 17 MSA patients and the clinical features of the two groups were compared. DAT specific binding ratio (SBR) were compared between severe and non-severe WMH groups, and between PD and MSA groups. The relationships of WMH with DAT availability and basic clinical characteristics were analyzed. Multiple linear regression analysis showed that age was the only significant variable showing correlation WMH. Age was the only clinical variable significantly correlated with WMH in PD patients (coefficient for periventricular white matter hyperintensity: 0.430, P = 0.007; coefficient for deep white matter hyperintensity: 0.381, P = 0.018). There was no significant correlation between WMH and SBRs and age in MSA patients. The SBR of the caudate nucleus and anterior putamen was significantly lower in the severe WMH group of patients than in the non-severe WMH group (P < 0.05). The values of the caudate nucleus, anterior putamen, and anterior putamen/posterior putamen were significantly lower in PD patients with than without severe WMH (P < 0.05), and the damage to the striatal DAT in MSA patients with severe WMH was similar to the non-severe patients (P>0.05). Patients with PD and a high WMH score had lower DAT availability. WMH affected the availability of DAT in patients with early to mid-stage PD compared to MSA.