Thispaperpresentsanexperimentalmethodformeasuringthedensityoftrappingcharges.Thismethodisbasedonthedy
namicequilibriumequationfortheprocessoftrappedcharges.WecanobtainthedensityandthelocationoftrappingchargesbymeasuringthehighfrequencyC VcurveofMOScapacitancebeforeandafterstress,andthechangeofgatevoltageunderconstantcurrentstress.Theanalyticalexpressionofthedensityoftrappingchargesisproposed .Themethodandtheresultsofparametersextractionarealsopresented .Experimentalresultsshowthatthismethodisconvenientandprecise .