Bicomponent microporous hollow fiber membranes consisting of polypropylene (PP) as an outer layer and polyethylene (PE) as an inner layer were prepared through the bicomponent melt spinning, drawing and annealing processes. Fibers of hollow shape were firstly prepared through the bicomponent melt spinning process by introducing the air into the core part of the fiber cross-section. Annealing and drawing processes were applied to thus prepared fibers to furnish the membrane properties. We have already reported that the PP single component hollow fiber membrane exhibits a practical level of air transmission rate when the fiber is prepared applying the drawing and annealing to the as-spun fibers which originally exhibits highly oriented and crystallized structure. On the other hand, our previous study on the structure development behavior of melt-spun PP/PE bicomponent fibers revealed that the fibers consisting of the PE component of high orientation and the PP component of low orientation were formed at low take-up velocities, whereas the structural feature reversed at high take-up velocities and the fibers with low orientation PE component and high orientation PP component were obtained. In this study, similar structural change with the take-up velocity was observed in the bicomponent spinning of PP/PE hollow fibers, where the reversing of the structural characteristics tended to occur at lower take-up velocities when PP component with higher viscosity was used. It is interesting to note that only the hollow fibers with highly oriented PP component exhibits high air transmission rate. This result indicates that the structure of PP component in as-spun fiber assume a crucial role on membrane properties in PP/PE bicomponent hollow fiber membrane.