The present invention relates to a method for compensating response time of liquid crystal display and a device therefor. The compensating method comprises: receiving gray scale data of a picture in present frame and obtaining a first additional driving value according to the comparison result between gray scale data of the picture in present frame and gray scale data of the picture in previous frame; collecting the temperature value of liquid crystal layer and obtaining a temperature driving value according to said temperature value; and generating a second driving value that is applied to pixels according to the first additional driving value and the temperature driving value. The compensating device comprises: a first additional driving value module for obtaining a first additional driving value; a temperature driving value module for collecting the temperature value of liquid crystal layer and obtaining a temperature driving value according to said temperature value; and a second additional driving value module for generating a second additional driving value. The present invention can effectively reduce the response time of liquid crystal display and mitigate the streaking problem.