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In this study, thin-film samples of semicrystalline block copolymer (BCP), polystyrene-b-poly(l-lactide) (PS−PLLA), were prepared by solution-casting from dichloromethane solution (1 wt % of PS−PLLA). As observed by polarized light microscopy (PLM), banded spherulites can be found in the PS−PLLA thin-film samples crystallized from melt. By contrast, no banded spherulites can be obtained in crystallized PLLA homopolymer under similar crystallization conditions. However, the formation of banded spherulites for PLLA homopolymer can be achieved by blending compatible poly(ε-caprolactone) (PCL) homopolymer. Also, blends of PS−PLLA and poly(d-lactide) (PDLA) were prepared; no banded spherulites can be obtained in crystallized blends having equimolar PLLA and PDLA (namely, racemic blends). As a result, we suggest that the effect of chirality on polylactide crystallization is necessary for the induction …