We conducted a neuromelanin sensitive magnetic resonance imaging, which is a good indicator for LC integrity, in 57 PD patients. We depicted a significant positive association between LC integrity and motor improvement after levodopa administration. We further confirmed this relationship in the level of objective brain alteration: LC integrity associated with the improvement of somatomotor network synchronization calculated from functional magnetic resonance imaging. We concluded that LC degeneration was an indicator for less levodopa responsiveness. LC integrity evaluation might be an alternative tool in predicting disease prognosis and stratifying patients into clinical trials for improving the efficacy of levodopa.