A radiation imaging apparatus comprises an imaging unit including a pixel array having a plurality of pixels, and a signal processing unit configured to process a signal from the imaging unit. Each of the plurality of pixels includes a conversion element configured to convert radiation into an electrical signal and a reset unit configured to reset the conversion element, the signal processing unit generates a radiation image based on a first image corresponding to an electrical signal converted by the conversion unit of each of the plurality of pixels in a first period, and a second image corresponding to an electrical signal converted by the conversion element of each of the plurality of pixels in a second period which starts after a start of the first period and ends before an end of the first period, and in each of the plurality of pixels, the conversion element is not reset by the reset unit in the first period.
