Experimental investigation of one-dimensional spatial distribution of photo-induced birefringence of azobenzene dye-doped polymers is reported. The orientational motion of chromophores and the consequential inter-molecular motion of the surrounding area are confirmed based on the spatial distribution and its evolution. It is found that orientational motion of chromophores and the consequential inter-molecular motion are dependent on the pump power and the size of the chromophores by the qualitative investigation of three kinds of azobenzene dye DR1, DR13 and DY7 doped PMMA polymers.