A test rig was designed and fabricated in this project to study the heat transfer of falling film flow on a doubly fluted plate. Parametric studies were performed to test the thermal performance based on the measured data. The effects of the temperature difference and feed water flow rate were studied with a given steam flow rate. The effect of steam flow rate was also studied under fixed feed water flow rate. During the testing, dry patches appeared on the plate surface when the feed water flow rate was less than 350 1/h. The measured results show that lower temperature difference, lower feed water flow rate and higher steam flow rate can increase the overall heat transfer coefficient. However, the effect of the temperature difference may have larger effect than that of the steam flow rate. This experiment results provide a good clue in the design of vertical tube falling film evaporators.