The temperature distribution and heat transfer coefficient of two-phase flow (water and air) through a rectangular ribbed channel was investigated experimentally and numerically for several values of heat flux (120,140,160 W), air and water superficial velocity (1.096, 1.425, 1.644, 1.864, and 2.193 m/s) and (0.0421, 0.0842, and 0.1474 m/s), respectively. The distribution of temperature along the channel was photographed using thermal camera and compared with images for the corresponding contours which found numerically. The experimental test system which consists of rectangular channel of 1m length with rib (heated plate) was located inside the channel. The temperature was measured by using a temperature sensor that placed at a various positions  on the side  test channel. A Sony digital video camera was used to image the flow inside the test channel. The Ansys fluent software 15.0 is utilized to simulate the governing equations with initial and boundary conditions. The percentage deviation between  the experimental and numerical data is (1.0% - 6.0% ). The experimental and numerical results of rectangular ribbed channel compared with smooth channel. The results proved that the flow is growing to become turbulent, eddies develop about the heated plate (rib), the temperature at the outlet decreases and  heat transfer coefficient improved by adding ribs, it also improved when the velocities of the flow increased.