In the kidney tissues and serum samples of the DM group as well as the supernatant of RMCs cultured with high glucose, the oxidative stress markers SOD, CAT, and GSH-PX were significantly decreased, while MDA was significantly increased, and CCK-8 showed an abnormal increase in the proliferation of RMCs, indicating the strong oxidative stress reactivity of diabetic kidney tissues and high glucose cultured RMCs. The gene discussed is CAT; the disease is diabetes mellitus.