A radiation imaging system capable of obtaining excellent image quality is provided. The radiation imaging system includes a detection unit (205) configured to include a plurality of pixels which are arranged in a matrix and which output pixel values by converting radial rays into charges and to output image information, driving control means (204) for causing the plurality of pixels to perform a resetting operation until a signal indicating irradiation with radial rays is supplied and to stop the resetting operation and perform an operation of accumulating charges when the signal indicating irradiation with radial rays is supplied, and for performing an operation of reading pixel values of the plurality of pixels after the irradiation with radial rays is terminated so as to output image information corresponding to the irradiation with radial rays, correction coefficient obtaining means (207) for calculating correction coefficients in accordance with the image information output from the detection unit, and image correction means (208) for correcting the image information output from the detection unit using the correction coefficients calculated by the correction coefficient obtaining means.