MgCl2-KCl salt has been widely employed as a heat transfer fluid in the thermal solar energy system. The corrosion behavior of 800H in MgCl2-KCl molten salt was investigated based on the long-term dipping corrosion test for 100 hours at different temperatures. The corrosion rates were calculated based on the weight loss, and they are 2.43, 3.57, and 4.58 mg/cm2/day for 700oC, 750oC, and 800oC, respectively. The samples were characterized using SEM equipped with energy dispersive spectrometer (EDS). The results shoed that Cr was found to be depleted on the alloy surface and also the concentration of Fe was decreased after the corrosion tests. Results were further discussed for its determination to be used as a structural material to contain such MgCl2-KCl molten salt.