Abstract: Photoresist is a key material in micro-fabrication for microstructure transferring during photolithography and protecting substrate during dry/wet etching. The photoresist developed using aqueous solution is more environmental friendly, which is the future of this type of materials. In this article, we focused on the KMPR resist, a type of epoxy photoresist which could be developed by either aqueous solution or organic solvent. We studied and compared the parameters and process of the aqueous solution (KOH and TMAH) or organic solvent (PGEMA) developing, mainly focused on the developing conditions for KOH solution and obtained an optimum KOH concentration and working temperature. And the mechanism of the developing process has also been interpreted.