A complementary metal-oxide semiconductor (CMOS) image sensor and a method of driving the CMOS image sensor that can reduce the number of devices required by each of a plurality of pixels and can stably drive the pixels, in which each of the pixels includes a photodiode that converts light energy into an electrical signal, a transfer transistor that transmits photocarriers stored in the photodiode to a floating diffusing region, a drive transistor that has a gate connected to the floating diffusion region and drives a voltage signal according to a voltage of the floating diffusion region, the voltage signal being output to an external device, and a capacitive device that is connected between a control voltage source and the floating diffusion region and, when a sensing operation of a corresponding pixel is terminated, deselects the pixel by altering the voltage of the floating diffusion region according to a control voltage provided by the control voltage source.