Abstract: Chinas rural village representation systemof village autonomy is an important part. This paper takes Wen villager of Puer city as research object, by using questionnaires and interviews, demonstrates relationship between rational decision-making costs and rational ignorance made by village representatives. The study concludes that, atpresent conditions, the village representatives in decision-making and problems analysis require new knowledge, but they can not afford the high cost,therefore, more village representatives maintain a rational ignorance. To improve the rational ignorance maintained by village representatives, we mustchange their conditions to access information and problem analysis, reduce their costs to participate in village representatives conference, which can be successfully implemented.