Studied activity of lysosomal ferments N-acetyl-p-D-glucosaminidase and P-D-glucuronidase in heart, liver and blood under influence of low intensive laser irradiation with A. = 470, A. = 570, X = 890 nm and different dozes in vivo on rats’ heart with acute focal myocardial ischemia. The effects of laser treatment (A, = 890 nm, with doze 2,4 J) on normal rat heart were reliable decreased free and combined enzymes activity, latentency, increased lability of lysosomes membranes in heart; decreased general enzymes activity in liver (permeability of the lysosomes membranes was stable). The effects of laser treatment with X = 470, 570 nm, with dozes 0,6-2,8 J on enzymes activity were not detect. Spectrograms of heart and liver lysosomes fractions after laser treatment were not detect special chro-mofores specific for A, = 470, 570, 890 nm. The influence of laser irradiation with 470, 570 nm and mostly with 890 nm on heart with acute focal myocardial ischemia exerted membrane-protective action; decreased general, free enzymes activity and permeability of the lysosomes membranes in heart and liver.