The intermediate annealed microstructure evolution in GH738 alloy after different rolling reductions was studied by OM, SEM, EBSD and HV tester. Results show that the strain hardening is mainly affected by rolling reduction. With different cold deformation degrees, austenite recrystallization does not occur when the annealing temperature is 1000 oC. The uniform, fine and equiaxed grains are obtained when annealing at 1040~1080 oC. The cold working constitutive equation and the recrystallization grain growth equation of GH738 alloy are established