This is a Phase 2, single-center, randomized, double-blind, placebo-controlled, parallel-group, 2-arm study in patients with mild to moderate PD. There will be three phases to the study. An initial 12-week screening phase was performed to determine eligibility. After informed consents, early-stage PD patients with Hoehn-Yahr stage 1 will be enrolled and participants will be asked to stop previously used anti-parkinsonism medications for at least one month to see the baseline disease severity. At the start of the study, participants will receive a comprehensive parkinsonism symptoms evaluation using Movement Disorder Society-Unified Parkinson's disease rating scale (MDS-UPDRS), global cognitive test using MMSE, and will be arranged for 18F-DOPA PET scan to evaluate the dopaminergic reserve in the striatum. Participants will also be asked to fasting for at least 8 hours to check the baseline laboratory test, including liver/renal functions, lipid profiles and serum CK level. Subjects will then be randomized to a 48-week double-blind treatment period of oral lovastatin 80mg/day or placeboSubjects in both groups will attend a further 5 clinic visits after 4, 12, 24, 36, and 48 weeks, where they are asked about their neurological symptoms and are evaluated by MDS-UPDRS. During the follow-up period, the dose of anti-parkinsonism could be added if both the patients and doctors thought the clinical condition deteriorated. Changes in PD medication as measured by levodopa-equivalent dose (LED) will be recorded at each visit. At final visit, patients will be arranged to receive the follow up 18F-DOPA PET scan to evaluate the dopaminergic reservation in the striatum and received MDS-UPDRS and MMSE evaluation. The secondary endpoints measured include MDS-UPDRS total scores, Part I and Part II sub-scores, the timing and dose of added anti-parkinsonism medication during the treatment period, the changes of 18F-DOPA PET uptake and MMSE scores, and global impression scale (GCI) of patients and investigators at the end of the study.