OBJECTIVE: To observe effects of moxibustion according to opening points on time in eight methods of intelligent turtle on aging and the mechanism. METHODS: Healthy and adult guinea pigs were randomly divided into 5 groups, a prevention group of kidney-yang deficiency model with eight method of intelligent turtle (group I), a prevention group of kidney-yang deficiency model (group II) with moxibustion at Mingmen (GV 4), a group of treatment group of kidney-yang deficiency model with eight methods of intelligent turtle (group III), a treatment group of kidney-yang deficiency model (group IV) with moxibustion at Mingmen (GV 4) and a control group of kidney-yang deficiency. Effects of moxibustion according to opening on time in eight methods of intelligent turtle and moxibustion at Mingmen (GV 4) on superoxide dismulase (SOD) activity and malondialdehyde (MDA) level were compared. RESULTS: After modeling, no signs of kidney-yang deficiency and no significant changes of SOD and MDA were found in group I and II; but obvious symptoms of kidney-yang deficiency and decrease of SOD (P < 0.01) and increase of MDA (P < 0.01 or P < 0.05) were found in group III, IV and V; after treatment, in the group III); the symptoms of kidney-yang deficiency basically disappeared, SOD increased (P < 0.01) and MDA decreased (P < 0.01), with no significant differences as compared with those before modeling (P > 0.05); in the group N, the symptoms of kidney-yang deficiency significantly improved and SOD increased (P < 0.05) with difference as compared with those before modeling (P < 0.05), and MDA decreased (P < 0.05), but with no significant difference compared with that before modeling (P > 0.05); the symptoms of kidney-yang deficiency, SOD and MDA did not significantly change in group V (P > 0. 05). CONCLUSION: Both moxibustion according to opening points on time in eight methods of intelligent turtle and moxibustion at Mingmen (GV 4) can effectively regulate free radical metabolism and have obvious action of preventing and treating kidney-yang deficiency in the model guinea pigs, and the therapeutic action of moxibustion according to opening points on time in eight methods of intelligent turtle is better than that of moxibustion at Mingmen (GV 4).