Abstract: Objective To develop a simple method for evaluating the stability of magnetic resonance (MR) scanner during brain function imaging. Method A symmetrical water phantom was scanned using the same sequence and parameters as for brain function imaging. The stability of MR scanner was evaluated in view of the signal levels of phantom images. Result The quality control chart of the mean value, standard deviation and the range of the signal level in the region of interest (ROI) within the same region on 128 phantom images were obtained, demonstrating the state of stability of the MR scanner. Conclusion The quality control chart of ROI can be used to evaluate the stability of the MR scanner.