The　study　device　is　the　latent　heat　storage　(LHS)　tank　which　is　developed　by　our　research　group　and　is　of　phase　change　temperature　80°C.　A　mathematic　model　is　set　up　for　heat　transfer　analysis.　The　research　group　investigates　the　effect　rules　of　thermal　perform　parameter　and　geometry　size　of　phase　change　material　(PCM)　which　is　the　heat　storage　body,　the　bulk　ratio　of　PCM　to　LHS　tank　and　velocity　of　water　which　is　the　heat　transfer　fluid　(HTF)　on　heat　charge　and　discharge　performance　of　the　LHS　tank　by　means　of　numerical　simulation.　The　analytic　result　shows　that　when　the　thickness　of　the　form-stable　flat-plate　PCM　is　about　8　mm,　the　thermal　conductivity　is　about　0.4　W/(m·K),　the　bulk　ratio　of　PCM　to　LHS　tank　is　65%-75%,　and　the　velocity　of　heat　transfer　fluid　is　0.005-0.008　m/s,　the　heat　charge　and　discharge　rate　of　LHS　tank　is　higher.