Abstract: Hot corrosion resistance of a new directional solidification superalloy with a thin film of 75% Na2SO4+25% NaCl was investigated at 750°C. The phase compositions of corrosion products were identified by X-ray diffractometer (XRD) and the surface and the cross-sectional morphologies of the samples were observed by scanning electron microscope (SEM). The results showed that the hot corrosion rate is high. With the increasing of hot corrosion time and the thickening of hot corrosion layer, the hot corrosion rate is lower. The corrosion products can be divided into three layers. The loose external layer is mainly formed by TiO2 and Cr2O3, the intermediate layer is Cr-rich and the internal layer is mainly oxides of Al and Ti with the dot-like sulfide. The hot corrosion of the alloy is a coexist process of oxidation and vulcanization, accompanied by some volatility of corrosion products. During the process, the corrosion expands to the matrix of alloy and makes the corrosion layer thicken.