Composite fibers of polyacrylonitrile (PAN) and hydroxyapatite (HAp) were prepared through a wet-spinning process for the purpose of using as a sorbent which can remove harmful cadmium ions from wastewater or food. HAp could be well immobilized in the PAN matrix in the fibers up to 50 wt%. Highly porous structure could be obtained by direct extrusion of the dope to water as coagulant resulting in density of the fibers lower to 0.38 g/$cm^3$. Thus radial pore channels were found to be well developed through the fiber, which is essential key-structure for the effective diffusion of metal ions from water-phase to inside of the fibers. The composite fibers showed maximum cadmium sorption amount of 12.3 mg per g of fiber and 30.7 mg per g of HAp.