In this paper, it is discussed that a pair of optical beams copropagates in no nlocal Kerr media, which is governed by the nonlocal nonlinear Schr?dinger equa tion (NNLSE). A new approximate linear model to the NNLSE is presented for the s trong nonlocal Kerr media with arbitrary response functions. An analytical solut ion in Gaussian form to the model is obtained. It is shown that the phase of eac h of the two beams is depended on the total input power. As a concrete example, th e interaction of two beams with the intensity of one of the beams much stronger than that of the other is discussed. It is found that the phase shift of the wea ker (probe) beam is very large within rather short propagating distance in the c ase of soliton, which can be controlled by modulating the input power of the str onger (pump) beam.