The effects of increasing Al+Ti content on microstructure and mechanical properties of IN 617 alloy before and after long time age heat treat were studied. The results show that increasing Al+Ti content contribute to more γˊphases and bigger size which can evidently influence strength, and we can achieve high tensile strength and stress rupture property. Compared to increasing Al content only, increasing Al+Ti content had better structure stability and long stress rupture life. The results indicated that IN 617mod2 alloy can be chose as one of candidate materials for A-USC rotor.