Energy　crisis　led　to　the　recognition　that　the　energy　conservation　is　important.　The　aim　of　performance　test　rig　of　a　water　chiller　which　is　introduced　in　this　paper　is　just　for　the　energy　saving.　In　order　to　get　the　better　efficiency,　a　monitoring　system　for　this　test　rig　was　developed.　The　design　idea　and　the　development　steps　of　the　system　would　be　introduced　in　detail,　and　this　might　be　helpful　for　the　design　and　development　of　the　small　and　medium-sized　automatic　control　system.　©　2009　IEEE.