Thermodynamic　optimization　models　of　gas-hydrate　cool　storage　and　cool　release　processes　are　established　in　this　paper.　The　optimal　temperature　configuration　at　the　sensible　heat　transfer　stage　and　the　optimal　gas　hydrate　phase　change　rate　configuration　at　the　phase　change　stage　in　the　processes　of　gas　hydrate　charging　and　discharging　are　obtained　by　taking　entropy　generation　minimization　as　optimization　objective.　The　optimal　control　strategies　of　the　cool　storage　system　are　determined.　The　research　results　indicate　that　the　optimal　operating　characteristic　of　the　gas-hydrate　cool　storage　system　can　be　achieved　by　keeping　the　phase　change　rates　uniform,　which　are　regulated　and　controlled　according　to　constant　heat　transfer　rates　in　the　charging　and　discharging　processes　of　gas　hydrate.　The　analysis　method　and　the　results　presented　in　this　paper　can　provide　important　guidelines　for　optimal　design　and　operation　of　gas-hydrate　cool　storage　system.　(C)　2009　Elsevier　Ltd.　All　rights　reserved.