It is proposed at the cycle of cascade plants for recondensation of liquefied gases vapor before each compressor to superheat at regeneration the vapor of working substance to corresponding temperature of condensation. Than the vapor is compressed isothermal to the pressure of condensation. This improvement decrease the necessary power of plant and the temperature of vapor after compressor and permits cool deeper the working sub-stance before throttling. Owing to this rise refrigerating coefficients of performance of the plant and improve conditions of compressors action. Modernization of cascade plants cycle for gas-carrier by cargo volume 75000 m3 permits to decrease its effective power on 22 %. It permits to economize at transportation of ethylene by to 5400 kWth and at transportation of ethane by to 3100 kWth of electric energy at day.