Room temperature tensile properties of polycrystal Ti-47Al-2Mn-2Nb alloy with near lamellar (NL) microstructures were investigated at the strain rates between 10(-5) and 1000 s(-1) using a self-designed Split-Hopkinson tensile bar setup with a rotating disk and conventional testing machine. It was found that tensile ductility varies within a narrow range with the strain rate, while dynamic strengths (sigma(d)) Of the alloy are obviously higher than static strengths (sigma(s)). There exists linear relationship between sigma(s) and the logarithm of the strain rate (In epsilon), and between sigma(d) and the strain rate itself (epsilon). Fractography analysis indicates that the alloy fractures in a mixed mode of predominant transgranular cleavage and minor intergranular cracking under static and dynamic strain rates. Environmental effect is excluded from the main cause for the room temperature brittleness of the investigated alloy.