Objective To explore the changes in the levels of mRNA N6-methyladenosine （m6A） and the related methyltransferase （methyltransferase-like protein 14 ［METTL14］） and demethylases （fat mass and obesity-associated protein ［FTO］ and AlkB homolog 5 ［ALKBH5］） in the blood of patients with Parkinson’s disease （PD） compared with healthy controls.Methods We consecutively enrolled 50 patients with PD at the inpatient and outpatient departments of neurology of the Affiliated Hospital of Jinan Medical University from January 2020 to June 2021， with 50 healthy participants as the control. The PD group and control group were compared with regard to the levels of METTL14， FTO， ALKBH5， and m6A in plasma and peripheral blood mononucleated cells （PBMC） by enzyme-linked immunosorbent assay， Western blotting， quantitative real-time PCR， and m6A methylation quantification assay.Results Compared with the control group， the PD group showed significantly lower levels of METTL14， FTO， and ALKBH5 proteins in plasma and significantly lower gray values of METTL14， FTO， and ALKBH5 protein bands in PBMC （all P<0.05）. The expression levels of METTL14， FTO， and ALKBH5 in PBMC mRNA were significantly lower in the PD group than in the control group （all P<0.05）. The PD group had a significantly lower m6A level in PBMC mRNA than the control group （P<0.05）.Conclusions Patients with PD have varying degrees of declines in METTL14， FTO， ALKBH5， and m6A levels in plasma and PBMC， suggesting a certain link between m6A and the development and progression of PD.