Under intravenous low level laser irradiation (ILLLI) of semiconductor green laser and He-Ne laser , we observed the SOD and LPO level of blood and its sustained effects so as to give some experiment data as theoretical evidence of clinical application. The results indicated that the density of SOD had a significant increase and the density of LPO had an apparent decrease after the irradiation. The effects caused by green laser were more obvious than those caused by He-Ne laser.