N-acetylcysteine (NAC) or tocopherol has been found effective as a therapeutic drug for improving intervertebral disc degeneration as well as low back pain and other diseases caused thereby. Oxidative stress has been revealed as one of the factors responsible for intervertebral disc degeneration. Hence, the present invention provides a method for screening for an intervertebral disc degeneration and/or low back pain drug targeting oxidative stress. Furthermore, an approach capable of quantitatively evaluating intervertebral disc degeneration using MRI images has been developed.