Poly(N-isopropylacrylamide) (PIPAAm) exhibits a reversible temperature-dependent soluble/insoluble transition at its lower critical solution temperature (LCST) in water. The [60]-fullerene-PIPAAm monoadduct (PIPAAm-C60) was synthesized by the azide addition using azido-terminated PIPAAm. Below LCST, the PIPAAm-C60 was dispersed and formed a micelle-like structure in water. Above LCST, the aggregation of the micelles was observed by turbidity measurements and dynamic light scattering (DLS). The PIPAAm-C60 exhibits rapid and reversible dispersion-agaregation changes in response to narrow range temperature alternation across LCST.