Abstract: Despite being currently one of the main internet application.P2Pfile sharing has been hampered by content pollution attack. To tackle this problem, we introduce a novel pollution control strategy that consisting in adjusting the rate in which content disseminated, according to content version reputation. The proposed strategy is modeled and evaluated using simplifying assumptions. Then inspired by classic distributed design, we propose a pollution control mechanism that implement such a strategy .The mechanism is evaluated in terms of the delay imposed on non polluted version dissemination when the version is polluted and the negative impact that collusion attack can impose on the reputation system upon which our mechanism is built.