The influence of the temperature on population dynamics of the rotifer Euchlanis dilatata Ehrb, raised in laboratory has been studied. The length of a generation, T, the net reproduction rate, R₀, and the intrinsic rate of natural increase (capacity for increase), r_c, have been determined at the fixed temperatures of 14°, 18°, 22° and at room temperature variable between 18° and 28°C. The latter condition has proved to be the optimal one as to the parameters R₀ and r_c.