A measurement system for measuring a motion picture response time (MPRT) of a liquid crystal display (LCD) has a computer and a measurement device. The computer controls a display panel of the LCD to switch between a plurality of different gray levels. The measurement device measures variations of brightness of the display panel when the display panel switches its gray level. The computer obtains at least a gray level response time (GLRT) normalized curve according to results of measuring the variations of the brightness. The computer integrates the at least a GLRT normalized curve to obtain at least an MPRT normalized curve, obtains at least a time interval of the at least an MPRT normalized curve, and calculates an average of the at least a time interval to obtain the MPRT of the LCD.