The crystallization behavior of poly(epsilon-caprolactone) (PCL) chains (i.e., PCL block + PCL homopolymer systems) spatially confined in nanocylinders with different diameters D has been investigated as a function of the mole fraction of PCL homopolymers f(homo) existing in the PCL chains. The nanocylinders with PCL chains inside were prepared using the microphase separation of PCL-block-polystyrene (PCL-b-PS) diblock copolymers with a photocleavable o-nitrobenzyl group (ONB) between PCL and PS blocks, and subsequently ONB was cleaved by a controlled irradiation of UV light to get the PCL chains with various f(homo). In the isothermal crystallization process, the crystallinity of PCL chains showed an exponential time evolution (or first-order kinetics) for all the systems investigated. The half-time of crystallization of PCL chains with 0 < f(homo) < 1 was found to be intermediate between those of PCL blocks (f(homo) = 0) and PCL homopolynners (f(homo) similar to 1); it decreased moderately with increasing f(homo) in a smaller nanocylinder (D similar to 14.9 nm) but increased slightly in a larger nanocylinder (D similar to 17.2 nm). We discussed the effects of tethered PCL blocks on the crystallization mechanism of PCL chains confined in nanocylinders on the basis of a general theory for polymer nucleation.