A series of polymers containing azo chromophores with different number of methyl substituents have been designed and synthesized．Three epoxy-based precursor polymers were prepared by reactions of diglycidyl ether of bisphenol-A with aniline

3-methylanifine

and 3

5-dimethylaniline respectively．The precursor polymers were reacted with diszonium salt at the final stage of the synthetic routes to introduce donor-acceptor type azo chromophores．The polymers synthesized were characterized by using various spectroscopic methods and thermal analysis．Photoprocessibility of photoinduced surface-relief-gratings on the polymer films was studied carefully．With the same irradiating light intensity and approximately equal film thickness

the rates of SRG formation significantly depend on the number of methyl substituents on the azo chromophores．For polymers with the same type of electron withdrawing group

the inscription rates decrease with the increase of the number of methyl substituents on the azo chromophores．