Heat transfer test rig had been built with pure water as heat transfer medium and air as heat transfer gas.Heat transfer experimental investigation on circle tube and staggered three-dimensional externally finned tube had been carried out.The building of test rig and experimental procedure had been introduced in details accompany with the theoretical model being derived for solving heat transfer coefficients.It was found that due to the special structure of staggered three-dimensional externally finned tube

its overall heat transfer coefficient is 3.1 times bigger than that of circular tube.By a linear regressive method

the experimental data were processed.The criterion relations of heat transfer were obtained and compared with circular tube.The results could provide reference for the industrial application.Finally

the deviation of the experimental data is analyzed and the result is believable.