An elevated temperature deformation test of industrial coarse-grained Ti-6Al-4V(TC4), which is for gas forming process, was conducted under the temperature of 880 ~ 980°C and the strain rate of 5×10-4mm/s, 1×10-3 mm /s, 5×10-3 mm /s, 1×10-2 mm /s. Based on the stress-strain curve of that material, the Johnson-Cook model, Exponential model, Series model, Parallel model and the Kumar model were established by using the regression analysis on stable deformation stage and whole strain stage (strain hardening stage plus stable deformation stage) respectively. The appropriate application circumstances of those models are analyzed. By using statistic analysis and aiming at minimizing the error rate between actual value and regression value, Kumar model is selected as the constitutive model of that material for gas forming test. Based on Kumar model, the industrial coarse-grained TC4 gas forming test was simulated by nonlinear finite element software Msc.Marc. The simulation results agree well with the actual parts. The Kumar model was appropriate and accurate.