<p>The nucleation and growth of {10–12} tensile twins in TA2 pure titanium during in-situ tensile test are explored by electron backscattered diffraction (EBSD). The dynamic process of twin growth can be clearly revealed by observe the evolution of microstructure at the same position with cumulative strains increases. According to the statistics and analysis of experimental data, it is found that the Schmid factor (SF) plays an important role during the nucleation and growth of twins. The twin variants with high SF are easy to be activated. However, approximately 18% of twins not satisfy the SF law, have low SF, nucleation and growth occur during deformation. In addition, the strain compatibility between tensile twins and various deformation modes in adjacent grains are analyzed by geometric compatibility factor. For tensile twin nucleation and growth, the shear strain generated by various deformation modes in adjacent grains plays an important role. The shear strain generated by tensile twins and pyramidal slip are beneficial to the twin nucleation, however, pyramidal slip is not conducive to the twin growth.</p> Graphical Abstract <p></p>