A radiation imaging apparatus, comprising a sensor array in which a plurality of sensors are arranged, each includes a first holding unit for holding a first signal obtained with a first sensitivity and a second holding unit for holding a second signal obtained with a second sensitivity, a row selecting unit for selecting each sensor on a row basis, a signal readout unit for reading out a signal from each of the selected sensors, and a control unit configured to perform first control to control the sensor array so as to make the first holding units hold the first signals and make the second holding units hold the second signals, and perform second control to control the row selecting unit so as to make the signal readout unit read out the first and the second signals.