Abstract: A computational fluid dynamics (CFD) program FLUENT was used to predict the fluid flow and heat transfer in channels of the plate-fin heat exchangers with plain fins and serrated fins.The calculation results indicated that the local coefficients of heat transfer for both cold and hot fluids in the heat exchangers with either plain fins or serrated fins had the maximum values at the entrance.The local coefficients of heat transfer and local pressure values for both cold and hot fluids changed abruptly at each staggered face of serrated fins.The thickness of boundary layer on serrated fins was thinner than that on plain fins.Both the local coefficient of heat transfer and pressure drops of fluids in the heat exchanger with serrated fins were larger than those in the heat exchanger with plain fins.