A liquid crystal display (LCD) device and a method of operating the same prevents a tearing effect from occurring. The LCD device includes a frame memory for writing new red, green and blue data or reading previously written red, green and blue data according to address designation, and a detector which outputs a cut off signal for cutting off operation of a light source controller or a gradation voltage generating portion when the new red, green and blue data are written to the frame memory before the written red, green and blue data are read from the frame memory.