Based on the real background of Wikipedia adopted as a classic peer production system and many users taking part in its editing,the two characteristics of preferential selection and limited matching during the editing process were considered.Two rules for “preferential selection” and “limited matching” and the evolving model of peer production system were presented.The analysis was based on computational experiments on the times of page editing,the status variation of pages and users,the affection of matching degree on page editing times,etc.The computational experiments show that the Wikipedia system evolves to a stable status under the action of the two rules.In the stable status,the times of page editing follow power law distribution; the difference between user’s status and page status(i.e.the matching degree)is toward to zero; the larger the matching degree of user and page,the smaller the power index of power law distribution,so the longer the tail of power law distribution.