Stimuli-responsive polymer materials have potential uses in drug delivery, tissue engineering, bioreactors, and cell-surface adhesion control. Temperature-responsive surfaces of triblock copolymers of poly(N-isopropylacrylamide)-b-polycaprolactone-b-poly(N-isopropylacrylamide) (P(NIPAAm)-b-PCL-b-P(NIPAAm)) were fabricated via atom transfer radical polymerization (ATRP). At 37 °C [above the lower critical solution temperature (LCST) of NIPAAm of 32 °C], the seeded cells adhered on the surface of the triblock copolymer, while below the LCST the cells detached from the surface spontaneously. P(NIPAAm) acted as the thermoresponsive segments of the triblock copolymer for control of cell adhesion and detachment. The thermosensitive copolymers are potentially useful as stimuli-responsive adhesion modifers for cells in biomedical felds.