Heat　transfer　characteristics　for　the　different　heat　transfer　surface　structure　at　the　different　pressure　conditions　were　investigated.　The　operational　pressures　in　this　study　was　in　the　range　of　0.86×105~2.0×105　Pa,　and　heat　transfer　characteristics　of　the　micro-channel　structure　and　sintered　screen　structure　were　experimentally　studied　and　compared.　The　experimental　results　showed　that　the　operational　pressure　has　an　significantly　effect　on　heat　transfer　coefficient.　Heat　transfer　coefficient　improved　with　the　increase　pressure　in　the　range　of　0.86×105~1.0×105　Pa　at　the　same　superheat　condition.　At　the　higher　operational　pressure,　heat　transfer　coefficient　first　improved　with　the　increase　of　superheat　then　dropped　after　reaching　a　certain　value.