In this paper, effects of solid solution treatment temperature on microstructure and tensile properties of casting SAF 2507 super duplex stainless steel were researched by means of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and tensile test. The results indicate that the amount of γ phase increases according to a linear relationship f(g ) = -0.134T +159.94 during the temperatures from 1100°C to 1250°C. Tensile properties of casting SAF 2507 super duplex stainless steel fluctuate with solution temperature change. Austenitic grain size and morphology are the most important factors on tensile property. The tensile strength is the highest owing to the finest austenitic grain at the solution temperature of 1150°C. The elongation is related to the fracture mode. At 1100 , elongation ration is highest because of the ductile fracture.