A solid-state imaging device and a method therefore capable of suppressing occurrence of motion distortion are provided. Each pixel includes a photo diode PD which accumulates a charge generated by photo-electric conversion in an accumulation period, a transfer transistor capable of transferring the accumulated charge in a transfer period, a floating diffusion FD to which the charge accumulated in the photo diode PD is transferred, a source-follower transistor which converts the charge of the floating diffusion FD to a voltage signal in accordance with the charge quantity, and a capacity changing portion capable of changing the capacity of the floating diffusion FD in accordance with a capacity changing signal, the capacity of the floating diffusion FD being changed by the capacity changing portion in a predetermined period in one readout period with respect to the accumulation period and a conversion gain being switched in this one readout period.