Novel cigarlike nanofibers with an outer-shell and inner continuous-pore structure and resultant fabrics have been fabricated by coupling the self-assembly of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) containing titanium precursors with the electrospinning technique in our previous work [You et al. ACS Appl. Mater. Interfaces 2013, 5, 2278]. In the current work, the structure control in these nanofibers has been investigated in detail using scanning electron microscopy, focused ion beam, and small angle Xray scattering. Our results indicate that electrospinning conditions, the adopted solvent, the volume fraction of PS-b-PEO block copolymer, and the amount of titanium tetraisopropoxide in the mixture produce significant effects on both outer-shell and inner-continuous structures in the nanofibers. The parameters discussed above make it possible to achieve programmable structure control in the aspect of the diameter, thickness of the outer shell, and inner continuous pore. As a result, both micropores among fibers and nanopores in certain fibers are under photocatalytic activity of resultant TiO2 fabrics was investigated by taking the photodegradation of Rhodamine B as an example. The results suggest that the degradation efficiency and rate constant exhibit sensitivity on the structure of nanofibers.