We investigate the effect of the dipole-dipole interaction on the dynamic properties and the atomic coherent trapping of a two-identical atom system in the presence of a laser field by means of quantum electrodynamics theory, The influence of the dipole-dipole interaction on the collapses and revivats of the atomic population is revealed. The conditions of the atomic eoherent trapping are given. A way to measure optically the coupling strength between the atoms is pointed out. Wc also show that the cffect of the dipole-dipole interaction may be screened duc to the coherent field in certain atomic superposition states.