As　working　fluid　of　heat　pipes,　water　is　widely　used　in　solar　heat　pipe　water　heater.　But　water　causes　poor　performance　of　heat　transfer　under　low　temperature　and　freezing　in　cold　winter.　In　this　paper,　ethanol-water　solution　is　used　as　working　substance　in　heat　pipe.　The　static　heat　transfer　and　start-up　performance　of　heat　pipe　are　experimentally　studied　in　this　paper.　The　experimental　results　showed　that　when　the　heat　flux　is　low,　the　heat　transfer　of　heat　pipe　with　40%　voluminal　concentration　ethanol　solution　is　better　than　that　of　heat　pipe　with　pure　water.　Start-up　speed　and　temperature　of　ethanol　solution　heat　pipe　are　higher　than　that　of　water　heat　pipe.　In　the　low　temperature　condition,　ethanol　solution　is　more　competent　than　water　for　working　medium　of　solar　heat　pipe.　In　addition,　heat　transfer　performance　is　also　influenced　by　incline　angle　of　heat　pipes,　charge　quantity　and　heat　flux.　The　effect　of　incline　angle　on　heat　transfer　performance　of　heat　pipes　becomes　distinct　with　the　increasing　of　heat　flux.　The　reason　is　that　the　heat　flux　becomes　high　and　reflux　condensate　becomes　much　with　the　increasing　of　heating　power.　The　optimal　incline　angle　of　heat　pipe　with　40　vol.　%　ethanol　solution　is　45°　and　the　optimal　charge　quantities　is　11.8　vol.　%.　The　experimental　results　are　helpful　for　widely　use　of　solar　heat　pipe　water　heater　in　north　China.　©　2010　by　ASME.