In this work we derive P wave equations for TTI media, starting from the exact dispersion equation for TTI media proposed by Tsvankin (1996). This new dispersion equations are valid for δ > ε (Thomsen’s parameters) and strong anisotropy. Using the new equations for pure P wave for TTI media, we migrated the BP-TTI synthetic data set with RTM technique with rapid expansion method (REM). It significantly improved the migrations sections when compared with migrations that did not take into account the anisotropy of the medium.