Poly(N-Isopropylacrylamide) is a typical temperature responsive polymer which exhibits a reversible hydrophilic-hydrophobic change in water at its lower critical solution temperature (LCST) of 32℃.It is reported that the PNIPAAm modified surface is also thermo-responsive, which have been used as HPLC packing material to separate compounds utilizing an aqueous mobile phase.In this report, Poly(N-Isopropylacrylamide) (PNIPAAm) was grafted onto silica surface via surface-initiated atom transfer radical polymerization(ATRP).The contents of PNIPAAm grafted onto the silica surfaces was 28.1% quantitatively determined by Thermogravimetric analysis (TGA).