The　water-enthalpy　method　cooling　capacity　source　could　be　applied　in　the　calibration　of　cooling　capacity　measuring　apparatus.　It　could　supply　a　cooling　capacity　which　was　measurable　and　controllable.First,　the　principle　of　water-enthalpy　method　was　illustrated,　then　the　physical　structure　of　the　source　was　designed　and　developed.After　that,　the　source　was　experimentally　investigated　in　an　air　enthalpy　method　test　rooms,　the　results　of　the　energy　transformation　of　fan＇s　electric　power　experiments　showed　that:　the　fan＇s　electric　power　transformed　into　thermal　energy　totally　and　the　energy　could　be　measured　by　air　enthalpy　method　test　rooms.Finally,　the　stability　experiment　and　the　evaluation　of　uncertainty　were　conducted,　the　results　showed　that　the　outputted　cooling　capacity　standard　deviation　of　30　min　was　22.2　W　(cooling　capacity　5251.9　W)　and　the　related　expanded　uncertainty　was　0.6%　(k=2).This　source　achieved　the　traceability　of　cooling　capacity　from　the　perspective　of　metrology　for　the　first　time,　and　the　cooling　capacity　could　be　traced　to　temperature,　pressure,　flow　rate　and　electric　power.　©　All　Right　Reserved.