The crystalline polypropylene hollow fibers were prepared by melt-spinning of polypropylene through a tube-in-orifice type nozzel and annealing process. Tensile strength, birefringence, density, and wide angle X-ray diffraction pattern of the hollow fibers were obtained for determining the effect of the preparation conditions such as draft ratio, spinning temperature, spinning speed, and annealing temperature on the degree of orientation and the crystallinity of the hollow fibers. The higher the draft ratio was, the more the orientation and the crystallinity increased. The hollow fiber spun at 190∼200℃ had higher degree of orientation than one spun at the higher temperature. After annealing process, the crystallinity was much increased while the degree of orientation was little changed. The hollow fiber membranes were made through drawing and heat treating the hollow fibers, and their performance was measured. The hollclw fiber membranes which had higher degree of orientation and higher crystallinity showed better performance. The scanning electron microscopy showed that the both sides of the hollow fiber membrane had the similar structure of pores and the pores had the shape of slit which was 0.3 μm long, and 0.1 μm wide.