With　the　development　of　distributed　technology,　security　problems　are　growing.　Trust　is　considered　an　effective　approach　for　enhancing　security　in　distributed　environment.　By　considering　fuzziness　and　uncertainty　of　trust,　we　propose　a　trust　quantification　algorithm　based　on　grey　fuzzy　comprehensive　evaluation　method.　Simulation　results　show　that　the　trust　quantification　method　can　reflect　nodes＇　real　trust　situation,　and　a　node＇s　trust　quantification　value　is　in　accord　with　its　behavior.　Copyright　2010　ACM.