The effects of laser irradiation on human and animal organisms have been intensively studied, but the mechanism of this effect is not well understood and discussed on the level of hypothesis. The effect of low-intensity laser irradiation (LILI) depends both on its physical parameters (wavelength, power density, time etc.) and on optical properites of irradiated tissues. The biological response on LILT started from the resonance absorption of irradiation by specific acceptors-enzymes, pigments and other biochemical structures containing in most cases chromophores. At the same time, distribution of absorbed energy between oscillated-excited states of atomic groups of macromolecules with following energy migration takes place too. Such effects induced changes in intensity of lipid peroxidation (LPO) and transitions of cell membrane confirmations with following changes of membrane enzyme activity (adenilate cyclase, ATPase) and ion permeability of membranes [1-3]. The effects of LILT on antioxidant system (AOS) of organism (the main components of this system are reduced glutathione (GSH) and enzymes - superoxiddismutase (SOD), catalase, glutathione-peroxidase (GP) ), have been described mainly for helium-neon laser (HNL) and are contradictory. From the other hand the irradiation by HNL induced activation of the AOS components [1 ,4]. It may be due to the activation of oxygen molecules by red light and, thereby, oxidative processes in tissues, or due to the effects on membrane functions, for example, membranes of red blood cells. At the same time, the effect of inhibition by this type of LILT or absence of any effect of LILT on AOS was shown by other researchers [4,5].