Located　in　YanshanMountain　and　stretched　across　the　Chao　River　and　Bairiver,　Miyun　reservoir　is　the　largest　artificial　lake　in　Asian.　Miyun　reservoir　is　well　known　as　Yanshan　pearl.　It　is　the　main　source　of　civilian　and　industrial　water　and　the　only　surface　water　source　of　drinking　water　in　Beijing.　Any　changes　of　the　Miyun　reservoir　will　affect　the　Beijingers＇　nerves.　A　survey　found　that　Miyun　reservoir　is　mainly　polluted　by　rainfall　runoff　(including　warehousing　rivers　and　reservoirs　sloping　runoff).　The　contrast　studies　of　Miyun　reservoir　upstream　gold　iron　mine　soil　heavy　metal　pollution　characters　show　that　the　soil　heavy　metal　content　in　gold　mine　is　much　higher　than　in　iron　ore　mine.　The　turn　of　soil　heavy　metal　pollution　degree　is:　Pb＞Cd＞Cr＞　Co　＞　Cu＞Zn　＞Hg　＞　As.　There　are　seven　big　tailings　ponds　surrounding　Miyunreservoir,　which　occupy　land　resources　in　long-term　and　destroy　landscape　vegetation.　The　heavy　metal　element　tailings　ponds　contain　will　cause　damage　to　the　surface　water　and　ground　water　and　atmospheric　environment.　So　it　has　important　social　value　and　scientific　significance　toensure　the　safety　of　the　tailings　by　strengthening　the　tailings＇　monitoring　and　safety　management.