Refrigeration　and　air　conditioning　(RAC)　system　Multi-evaporator　structures　are　popularly　applied　in　for　efficient　temperature　and　humidity　control　of　multi-zone　in　underground　buildings,　light　commercial　and　residential　buildings,　cold　stores,　et　al.,　which　can　also　attract　and/or　release　heat　from　and/or　to　renewable　sources.　The　increase　on　the　system　complexity　makes　it　difficult　to　analyze　the　performance　and　to　optimize　its　design　and　control.　In　this　paper,　a　novel　method,　performance　chart,　is　presented　for　the　performance　analysis　and　system　optimization　of　multi-evaporator　and　RAC　systems.　The　performance　chart　is　generated　by　superimposing　the　performance　curve　of　different　evaporators　of　the　indoor　unit　(IDUs),　which　can　be　applied　to　describe　the　performance　of　the　whole　RAC　system　by　superimposing　with　the　performance　curve　of　outdoor　units　(ODUs).　Based　on　the　performance　chart,　the　performance　of　multi-evaporator　systems　are　analyzed　at　different　conditions　such　as　varying　indoor　temperatures,　varying　indoor　air　volumes,　and　varying　IDUs＇　capacities.　The　performance　chart　can　give　the　reasonable　and　quantitative　trends　of　multi-evaporator　RAC　system　performance　and　guide　the　system　design.　These　results　showed　that　the　performance　chart　can　be　used　as　a　convenient　tool　for　performance　analysis　and　system　optimization　of　multi-evaporator　RAC　systems.