The problem of amplification of the drift solitons in plasma with inhomogeneous density and temperature is studied theoretically. Resonant interaction of solitons with electrons and effect of finite electron thermal conductivity are considered as possible causes of amplification. It is concluded that the resonant interaction does not lead to the soliton amplification. It is due to trapping of resonant particles in a potential well of the soliton. It is shown that the finite electron thermal conductivity causes an amplification of the drift solitons comparable with that of the linear drift waves.