Development of bicomponent spunbond nonwoven consisting of ultra-fine splitted polypropylene (PP) and polyethylene (PE) fibers was described. The morphological structures developed in bicomponent spinning of PP/PE fibers with the cross-sectional configuration of "sixteen-segment hollow pie" were investigated in relation to molecular properties as well as the resulting fiber splittability. Structure developed in each component in the melt spinning process was found to depend not only on its molecular properties but also on those of the other component. Results showed that the PP/PE pair exhibiting good splittability possesses high molecular orientation in both components.