The austenitic stainless steel samples containing residual δ ferrite were solution treated at different temperatures. The SEM, EBSD, TEM and hardness tester were applied to investigate the microstructure, texture, hardness and precipitate phase characterization of the experimental samples. The results show that there are three phases of austenite, ferrite and sigma in austenitic stainless steel after solution treatment at 900~1100℃ for 30min. M23C6 and Chi phase are not found. The sigma phase forms in the range of 900~1000℃, which also enhances the hardness of the matrix. Sigma phase is mainly formed by decomposition of residual δ ferrite. The {001}<110> and {001}<100> oriented δ ferrite preferentially transforms to sigma phase. With the increase of temperature, the content of sigma decreases, the average grain size of austenite increases, and the hardness decreases gradually. After 1050℃, sigma phase is completely dissolved into austenite, and the average grain size of austenite grows significantly. This results into the hardness decreases rapidly. Meanwhile,{001}<110> and {001}<100> textures of δ ferrite were re-enhanced。After solution treatment at 1100℃, the content of residual δ ferrite decreased to 0.2%.