Grain refinement is a challenging topic to improve mechanical properties of metallic materials, especially for titanium alloys which show great potential in aerospace and medical implants areas due to the low density and good corrosion resistance. However, severe plastic deformation (SPD) technologies which have been commonly used in laboratory in smaller scale are difficult to be realized in industrial. Considerable researches are therefore paying attention to the development of new technologies for improvement of grain refinement at relatively lower strains. In this work, the dual phase TC16 titanium alloy showing excellent room temperature ductility was investigated with emphasis on the feasibility of producing ultrafine grains by roller die drawing at room temperature. The techniques of XRD, SEM, TEM, Vickers hardness test and tensile test were employed to analyze the phase constitutes, microstructure evolutions and preliminary mechanical properties of the alloy deformed at different conditions. Results reveal that TC16 titanium alloy mainly consists of α and β phases after roller die drawing at room temperature, and a small quantity of stress-induced α" martensite can be additionally identified inside β grains. The grain sizes of α phase and β phase decrease with strain increasing, which result to enhanced tensile strength and Vickers hardness. Indeed, the fibrous morphology of both α phase and β phase with 0.3 μm in thickness and a high value of 365 HV in Vickers hardness were revealed at the applied true strain of 2.14. Ultra-fine grains evidenced by a near-ring SAED spots were therefore achieved in the present case.