We　investigate　the　entanglement　dynamics　of　an　entangled　atom　pair　via　Wootters＇　concurrence.　Only　one　atom　of　the　pair　interacts　with　a　two-mode　cavity　field　via　a　Raman　interaction.　The　number　simulation　shows　that　the　entanglement　of　the　atom　pair　will　display　sudden　death　and　revival　phenomena　when　the　cavity　photon　numbers　and　the　two-mode　atomcavity　coupling　strengths　are　changed.　Due　to　the　two-mode　field　effect,　the　entanglement　sudden　death　phenomenon　will　disappear　more　easily　by　enlarging　the　different　cavity　modeatom　coupling　ratio.　The　oscillation　rate　of　the　concurrence　is　enlarged　by　increasing　the　mean　photon　number　of　the　cavity　field.　©　2012　The　Royal　Swedish　Academy　of　Sciences.