Deformation modes of quenched β Ti–16∼27%V alloys are investigated in compressive and tensile tests as a function of crystallographic orientation and deformation temperature. The {332} twinning takes place in the low vanadium content alloys. By analysing the twinning systems appearing in compressive and tensile tests, the polarization of twinning shear is confirmed to occur in the {332} twinning. The {332} twinning is suppressed by aging or oxygen addition. It is suggested that the formation of the {332} twinning is due to the instability of the β phase of Ti–V alloys containing some interstitial impurity atoms. On the other hand, deformation occurs by slip in the alloys with high content of V. These alloys exhibit an asymmetry of both the yield stress and the slip plane, the degree of asymmetry being larger at 77 K than at 300 K.