The photosensitive polyamide precursors were synthesized from pyromellitic acid dich-loride di(o-nitrobenzyl) ester with o-nitrobenzyl group and two amines such as m-phenylene diamine and m-diaminobenzophenone by interfacial polycondensation reaction. The polymers obtained were able to be converted into usual polyimide by curing The photoreaction mechanism of photosensitive polyimide precursors was investigated by UV and NMR spectroscopy. It was considered from the absorbance of UV at 23O~28Onm that characteristic rearrangement in the o-nitrobenzyl ester occurred m this system. Their thermal properties were studied using thermogravimetry, both polylmide precursors exhibited the weight loss in two stages. The second weight loss depends on the thermal degradation of polyimide. Noticeable weight loss was observed at about 500˚C. After preparing photoresist from these polyimide precursors synthesized, normalized thickness remaining were measured with varying exposure energy to determine whether the polymers can be used as a commercial photoresist.