Abstract: There are many generalizations to AdS/CFT duality which in its original form is a correspondence between a 4-dimensional strongly coupled super-conformal Yang Mills (SYM) theory and a gravity theory in AdS5*S5 background. This correspondence can be generalized to thermal SYM theories and also matter fields (quarks) can be added to the theory at the same time. In This talk we conduct a brief review of thermalization process in the flavor sector of field theory which is due to introducing a time dependent coupling in the field theory. This goal is achieved by studying the dual process in the gravity theory and corresponding thermalization process in flavor sector to horizon formation on the worldvolume of the probe branes.