In this paper, hot deformation behavior of as-cast TC17 titanium alloy was investigated by isothermal hot compression tests at temperatures of 1073~1373K and strain rates of 0.01~20s_^-1. The four constitutive models, strain compensated Arrhenius-type (SCA), modified Arrhenius-type (MA), Johnson Cook (JC) and Modified Johnson Cook (MJC), were used to represent the elevated temperature flow behavior of as-cast TC17 titanium alloy. The suitability levels of these models were evaluated by comparing both the correlation coefficient R and the average absolute relative error (AARE). The results indicated that JC model the JC model is inadequate to predict the flow stress of as-cast TC17 titanium alloy; the SCA model has the highest accuracy to descript of flow behavior of TC17 alloy in the α+β two-phase region in the studied range. While the MJC model exhibits the highest accuracy in the β single-phase region. Within the whole deformation temperature range, the SCA model proposed in this paper can more accurately conform to the high-temperature rheological curve of as-cast TC17 titanium alloy.