The two phase closed Thermosyphons are highly sufficient heat transfer element At present. however, actual applications are mostly limited for thermosyphon using smooth tube as its container. In the present work, a corrugated. tube was used as its container with distilled water as the working fluid. The corrugated tube container is flexible and has several features to allow the thermosyphon to be used in a wide range of applications The influence of liquid filling ratio, inclination angle, evaporator heat flux and condenser to evaporator length ratio on the heal transfer performance was experimentally studied The experiments are carried out for values of heat flux of 11, 20,5. 32.8. 44 kW/m2, Filling ratios of 20,40.60, 80 and 100 % with respect to evaporator volume for thermosyphon configuration arc used. The effect of inclination angle of zero, 20, 40, 60, 80 and 90 degrees measured from the vertical axis is examined. Three different values (or length ratios between condenser to evaporator of I, 1.5 and 3 are used. According to the measured values of problem parameters, the mean heat transfer coefficient is calculated. it is found that the optimum filling ratio is in the range o( 40-60 % for both smooth and corrugated tubes. in addition, the maximum performance is Obtained at inclination angle of 40 degree Moreover. a comparison is made between corrugated tube and smooth tube at the same tested parameters.