Thermo-induced structural reorganizations in thrombocytes' membranes in the presence of aggregation inductor ADP and aggregation inhibitors--aspirin or alpha-tocopherol at the temperature range of 0-40 degrees C above zero, have been studied by mean of spin probe. It has been shown that in this temperature range alpha-tocopherol decrease structural flexibility of phospholipid fatty acid residua and increase the parameter of order S of 5-doxilstearin probe. ADP and aspirin increase structural flexibility of fatty acid residua of this cells. The temperature plots' study of 2A'11 parameter in EPR, proportional to parameter of order S made possible to find out essential difference between influences of these substances to thrombocyte membrane. The aggregation inductor ADP results in removal of the curve bent-point in Arrhenius coordinates to the lower temperature region (17-13 degrees C) when aspirin and alpha-tocopherol induce either low temperature removal of the bent-point and formation of the supplementary bent in higher temperature region (28 degrees C for alpha-tocopherol, 20 degrees C for aspirin). Such differently directed changes of parameter of order under the aggregation inhibitors' influence is probably connected with different mechanisms of their antiaggregation activity.