The　temperature　characteristics　and　their　effect　factors　of　a　radial　eccentric　gravity　heat　pipe　were　investigated　experimentally　under　natural　convection　and　forced　convection.　For　the　test,　a　radial　eccentric　gravity　heat　pipe　was　fabricated　with　two　eccentric　pipes　of　unequal　diameters　that　create　an　annular　vapor　space.　The　radial　eccentric　heat　pipe　was　sealed　with　a　high　vacuum　valve　by　which　the　filling　ratio　could　be　changed.　The　experiments　were　performed　in　the　range　from　70　to　100　and　filling　ratios　(FR)　from　15%　to　60%.　The　temperature　stability,　uniformity　and　distributions　of　the　outer　surface　of　the　outer　pipe　and　the　inner　surface　of　the　inner　pipe　were　affected　by　various　factors,　such　as　filling　ratios,　the　locations　of　the　heater　controller　probe　and　the　cooling　capabilities　of　the　inner　pipe.　The　wall　temperature　distributions　on　both　the　outer　surface　of　the　outer　pipe　and　the　inner　surface　of　the　inner　pipe　were　monitored　and　analyzed.　The　results　indicated　that　the　temperature　stability　of　the　inner　surface　of　the　inner　pipe　was　about　±0.024　for　2　h.　The　maximum　temperature　difference　was　0.142　over　20　cm　in　the　central　part　of　the　measuring　zone　and　the　minimum　temperature　of　the　outer　surface　of　the　outer　pipe　appeared　underneath　the　inlet　of　cooling　air.　The　results　also　showed　that　the　radial　eccentric　gravity　heat　pipes　were　very　promising　in　the　applications　of　temperature　calibration　field.　©　All　Right　Reserved.