Titanium alloy grade Ti-6Al-4V has been widely applied for many applications such as aircraft structural components, machine parts, and parts for medical equipments. To understand deformation behavior and microstructure evolution of the material during hot forming process is significant for achieving desired dimension and final mechanical properties of a product. In this study, stress-strain responses of the Ti-6Al-4V alloy were investigated using hot compression tests at different temperatures and strain rates. The determined flow curves of the alloy were subsequently calculated according to the constitutive models based on Cingara equation and Shafiei and Ebrahimi equation and compared with the experimental results. By this manner, influences of work hardening and dynamic recrystallization on the hot deformation behavior of material could be described. Accurate prediction of flow curves can considerably improve the forming process design.