Based　on　the　data　of　Beijing　bus　operation　and　energy　consumption,　the　characteristic　relationship　of　bus　service　level　and　energy　consumption　are　quantified　from　the　perspective　of　bus　types,　travel　speed,　load　rate,　and　bus　lanes.　The　research　shows　that　there　is　negative　correlation　between　the　bus　speed　and　the　energy　consumption　per　100　km,　but　an　obvious　negative　correlation　between　bus　loaded　rate　and　the　energy　consumption　per　10　000　passenger-kilometers.　For　different　bus　types,　the　energy　consumption　per　100　km　of　the　single　bus　is　about　30%~40%　less　than　that　of　the　double　decker　bus,　but　the　energy　consumption　per　10　000　passenger-kilometers　of　the　single　bus　is　about　5%~15%　higher　than　that　of　the　double　decker　bus.　Finally,　using　the　travel　speed　and　load　rate　as　the　main　parameters,　the　energy　consumption　model　of　bus　based　on　the　service　level　is　constructed　and　applied　for　case　study　of　bus　energy　conservation.　The　result　indicates　that　when　the　loaded　rate　is　above　60%,　the　decrease　of　energy　consumption　per　10　000　passenger-kilometers　is　slowing　down.　And　when　the　average　travel　speed　is　lower　than　40　km/h,　increasing　speed　of　buses　can　reduce　energy　consumption　per　capita.　Copyright　©　2018　by　Science　Press.