We developed a diagnostic method for Parkinson's disease by simultaneously analyzing biogenic amines and their metabolites using reverse-phase high-performance liquid chromatography coupled with integrated pulsed amperometric detection (RP-HPLC-IPAD) method. Dopamine (DA), 3, 4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA), and homovanillic acid (HVA) were used as biomarkers to diagnose Parkinson's disease. All target components were detected with good sensitivity using sodium hydroxide (as a post-column eluent). The limit of detection (S/N = 3) and limit of quantification (S/N = 10) of the target components ranged from 0.020 to 2.400 ng and from 0.080 to 8.000 ng, respectively. The coefficients of linear regression ranged from 0.9996 to 1.0000, all inter-day and intra-day precision values were <3.43%, and the average recovery and RSD ranged from 97.55 to 103.60% and 0.22 to 4.79% for mice striatum samples. This method exhibited good selectivity, sensitivity, and reproducibility and can be used directly without any pretreatment steps. Our method will be useful as a tool to diagnose Parkinson’s disease.