The problem of the electron tunneling through the interface carbon nanotube/ graphene in the presence of a strong oscillating electric field was considered. An approach was developed to overcome the standard restrictions of the Kubo theory. A system of equations for mean values of number of particles describing the tunneling process was obtained. The current-voltage characteristics for a weak external field were constructed. The case of strong exposing field was analyzed and compared with the weak external field approximation. Modulation of current in the presence of external oscillating field was found.