Focusing　on　the　dynamic　measurement　issues　of　the　interactive　behavior　of　a　software　system,　a　dynamic　measuring　model　based　on　the　dependent　relationship　among　input　variables　was　presented.　Beginning　with　the　analysis　of　influence　to　the　trust　caused　by　the　input　data　and　by　adopting　the　static　analysis　technology　on　source　code　and　program　slicing　technology,　the　forward　slice　set　about　the　input　data　of　program　as　well　as　the　variable　set　that　can　be　written　by　each　statement　in　the　slice　set　were　extracted.　Then,　the　expected　behavior　model　was　produced　by　taking　the　statements　in　the　acquired　slice　set　as　the　dynamically　measured　objects,　and　the　variable　set　assigned　by　the　corresponding　statements　as　the　expected　behavior.　During　the　execution,　the　model　verifies　whether　or　not　the　target　program　behavior　consists　with　the　behavior　specification.　Finally,　test　result　shows　the　effectiveness　of　the　model.