The kinetics of crystal growth and nucleation have been studied for melt crystallization with direct contact cooling. Three kinds of direct contact coolants such as air las gas), water las liquid) and butane las liquified gas) were investigated. The contribution of heat transfer to overall crystal growth process has been studied. The melt crystallizers with direct contact coolants can be operated batchwise and continuously. It is shown that growth rates increase with the square of the supersaturation, and high subcooling (> 7.5 K) induce crystal agglomeration. The presence of direct contact coolants does not affect the nucleation characteristic due to their immiscible and inert behavior with the melt. Evaluation was carried out in terms of effectiveness factor and Mersmann＇s growth rate theory based on the mass transfer step for two coolants. It can be shown that the growth of crystals is controlled by heat transfer for gas coolant, while mass transfer is decisive for liquid coolant.