GH4169 is a superalloy widely used in important fields, such as aviation and nuclear power. In addition to controlling the forging process, modifying the microstructure and enhancing the stability of the alloy via heat treatment is also an important way to improve its mechanical properties. Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile tests were used to study the changes in the microstructure and tensile properties of the GH4169 alloy after solution treatment at 960~1 020 ℃ followed by aging at room temperature and 650 ℃. The results show that the solution temperature significantly affects the microstructure of the alloy. When the solution temperature increases from 960 to 1 000 ℃, a large amount of the δ phase in the alloy dissolves, resulting in rapid growth of the matrix grain size. Owing to the increase in solute elements in the matrix, the amounts of γ′ and γ″ precipitates increase during the subsequent aging treatment. The reduction effect resulting from the increase in the grain size on the mechanical properties exceeds the strengthening effect caused by the increase in the number of strengthening phases. Compared with the alloys aged after solution treatment at 960 and 980 ℃, those subjected to solution treatment at 1 000 and 1 020 ℃ prior to aging present reduced yield strengths at both room temperature and 650 ℃.