In th is paper, som e econom ic characterist ics of pub lic u t ility en terp rises are summ ed up , a model of p rincipal2agen t theo ry betw een governm en t b ranches and the en terp rises is p ropo sed. It is p roved th rough the gam e analysis that the governm en t budget po licy is the key reason to arise st im u lat ion feeb le and co st increasing fo r the en terp rises under the p laned econom ic system. The in it ial refo rm , though w ith som e defect s, imp roved the eff iciency of the u t ility en terp rises, and show s that it shou ld be an inevitab le layou t fo r u t ility en terp rises to estab lish modern en terp rises system and to fo rm alize the p rincipal2agen t relat ion sh ip betw een the governm en t b ranches and pub lic en terp rises.