[en] The mechanism of emission of light particles in heavy ion reactions at approximately 10 MeV/nucleon is investigated. The contribution of evaporation mechanism has been calculated. A model for the description of high energy part of emission spectrum is proposed. The results of theoretical calculations are compared with the experimental data on emission of neutrons and alpha- particles. The results of the calculation of energy neutron spectrum in ¹⁸¹Ta+²²Ne and ¹⁵⁸Gd+¹²C reactions as well as energy spectrum of alpha particles in the ¹⁸¹Ta+²²Ne reaction are presented. The cross section of the heavy ion reaction of above energies consists of preequilibrium as well as evaporation components. In the ¹⁵⁸Gd+¹²C reaction the transition from the evaporation component to the preequilibrium one manifests more clearly than in the ¹⁸¹Ta+²²Ne reaction