This paper analyzes the mode field distributions of TE 0 mode and TE 1 mode of plane wave guides by the two dimensional vector finite difference time domain (FD TD) method.Five kinds of optical sources are used as stimuli when analyzing TE 0 mode,and the final results of optical field distributions are the same after the standy spreading of optical waves.Furthermore,the two dimensional mode field distributions of TE 0 mode and TE 1 mode under stable state is identical to that discussed by the analytic methods.