In order to examine the antioxidant action of Loranthus parasiticus (L.) merr (LP), the study was done through measurement of parameters such as LPO, GSH, SOD, catalase, GOT, GPT and ALP. The results were obtained as follows: For the weight changes, in the left cerebrum, right cerebrum, cerebellum and testis, the group given LP showed small increase compared to the control group. But the weight changes were not significant. In the left cerebrum, the group given LP showed significant decrease compared to the control group in the content of LPO and significant increase compared to the control group in the activity of SOD. But in the right cerebrum, cerebellum the changes were not significant. For the changes of contents of SOD and catalase in the liver, the group given LP showed significant increase compared to the control group. For the changes of the activity of SOD in the kidney, the group given LP showed significant increase compared to the control group. For the changes of contents of LPO and GSH in the spleen, the group given LP were showed no significant decrease compared to the control group. And for the changes of the activities of SOD and catalase, the group given LP showed no significant increase compared to the control group. For the changes of content of LPO in the testis, the group given LP showed significant decrease compared to the control group. And for the changes of the activity of catalase, the group given LP showed significant increase compared to the control group. For the changes of GOT, GPT in the serum, the group given LP showed significant decrease compared to the control group. From above results, the antioxidant action of LP is effective. And it is expected to be necessary to the study of the mechanism in the antioxidant of LP.