Disclosed is a method for integrating an image sensor capable of removing a flicker noise without causing any burdens on a hardware due to setting up additional logics. The method for integrating an exposure time of an image sensor employing a line scan method, including the steps of: performing an integration to a first line when an integer multiple of a light source frequency is different from an integration time; and performing an integration to a second line at a phase substantially equal to a phase in which the integration to the first line is started.
