Heat　meter　without　flow　meter　is　a　new　kind　of　measurement.　It　avoids　the　perishable　and　inaccuracy　of　a　heat　flow　meter　which　is　used　when　the　quality　of　heat-conveying　water　is　poor.　Through　the　method,　the　heat　flow　can　be　estimated　and　calculated　simply　by　measuring　the　temperature.　However,　the　method　of　heat　meter　without　flow　meter　must　measure　the　temperature　of　indoor　air,　which　makes　trouble　of　measurement.　Therefore,　a　radiator　room　model　is　established　by　using　Fluent　software.　The　average　temperature　of　radiator　room　is　derived　by　using　the　finite　volume　method.　And　the　functional　relationship　between　the　average　temperature　of　the　radiator　room,　the　inlet　temperature　of　radiator　and　the　flow　of　radiator　is　established　through　Matlab　&　Maple　software.　After　bringing　the　functional　relationship　to　the　model　of　heat　meter　without　flow　meter,　the　correctness　of　the　functional　relationship　is　tested　through　the　results　of　simulation.