Wall thickness is constant in the axial direction when aluminum tubes are formed by conventional extrusion process. Tubes with internal ribs have high strength in comparison with those without ribs. These tubes can be used, for example, as structural parts, heat sinks, and impact absorbers. The existence of some holes at ribs enhances the function and value of the tubes. The appropriate positioning of holes at ribs reduces the weight of structural parts without strength reduction. In the case of heat sinks, holes change the fluid flow and would realize effective heat transfer. In this research, a new extrusion method is proposed by authors for manufacturing tubes with holed ribs. A new extrusion method is applied by FEM analysis. Model experiment was carried out based on the results. The method involves the use of a unique mandrel that has a slit along its axis and two guides at the slit exit. A holed sheet is fed through the slit and joined to the inner surface of the tube. In particular, the effect of the guide height is clarified in this study.