A　multiple　energy　source　air-conditioning　system　was　developed　for　large　office　buildings　in　Beijing,　China　to　reduce　the　energy　consumption　and　improve　the　energy　utilization　in　public　buildings.　Three　systems　are　compared　with　an　air　source　heat　pump　system,　a　ground　source　heat　pump　coupled　with　an　air　source　heat　pump　system　and　a　solar　assisted　ground　source　heat　pump　coupled　with　an　air　source　heat　pump　system.　Cost-benefit　analyses　are　given　for　each　type　of　air　conditioning　system.　The　building　load　was　computed　using　the　DeST　simulation　software.　Economic　indicators　are　used　to　evaluate　the　systems　economics　in　terms　of　the　initial　investment,　life　cycle　cost　(LCC),　operating　cost,　payback　period,　energy　conservation　rate　and　cooling　and　heating　cost　in　hourly　moments.　The　results　indicate　that　the　multiple　energy　sources　system　has　better　energy　conservation　and　economics.　For　a　solar　heating　fraction　of　40%　to　building　loads,　the　required　solar　heat　collector　area　is　135　m(2),　the　energy　conservation　rate　is　43.18%　and　the　payback　period　is　2.76　years.　Although　the　initial　investment　is　greater　than　for　the　other　systems,　the　operating　costs　are　lower　at　65,932　CNY/year　and　LCC　is　lowest　at　863,300　CNY.　The　lowest　heating　costs　among　the　three　systems　are　at　760　CNY/kJ.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.