Heat transfer and pressure drop characteristics of the welded plate heat exchangers are experimented to apply the high- and low-temperature solution heat exchanger (SHX) of absorption systems. Two different SHXs were made using the seam and tig welding method. In this paper, the welded embossing type plate heat exchangers were tested by controlling mass flow rate and inlet/outlet temperatures. It was found that heat transfer and pressure drop performance increased with increasing Reynolds number. It was also found that the pressure drop from the present W-embossing type plate heat exchanger was much lower than that from the brazed type, as low as 1/7 times. The experimental correlations for Nusselt number and Fanning friction factor were developed with the error bands of ${pm}$ 20% and ${pm}$ 25%, respectively. These results provide a guideline apply the welded plate heat exchanger for the solution heat exchanger of absorption systems.