A method and system for measuring the response time of an LCD are provided. The method comprises the following steps: step A: controlling the LCD to display a preset image; step B: obtaining the luminance of the LCD that is displaying the preset image, and outputting a luminance-time curve in which the luminance changes over the time; step C: correcting the luminance-time curve to obtain a corrected luminance-time curve, and calculating the response time of the LCD according to the corrected luminance-time curve. When implementing the present application, the measuring errors about the response time of the system for measuring the response time, which are resulted from using different actual luminance measuring devices, can be reduced or eliminated.