In this study, features of neural signal recordings with microelectrode injected into the internal globus pallidus of non-human primates before and after 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) treatment which induces Parkinson’s disease (PD) were investigated. Neural oscillations were analyzed using the measure of wavelet spectrum and singular value extraction. Differences in the time-frequency analysis were observed between groups. Results showed that the PD states had significantly higher amplitudes of spectrum. Singular values extracted from wavelet coefficients after wavelet package decomposition were used to differentiate pathological changes from normal states, and the singular values of the reconstructed wavelet coefficients of the PD states were statistically smaller than controls. We speculate that the irregular high frequency oscillations and reduced singular values observed in the pathological firings are consistent with the previous view that a loss of information transmission in the neural circuitry underlies PD and these measurements could be of diagnostic and monitoring values of the disease state.