Transport properties of the comb-type grafted and normal-type N-isopropylacrylamide (NIPA) gel are investigated by gel filtration chromatography and a pulsed field gradient NMR technique with known standard probe molecules in terms of molecular weight cutoff and diffusion coefficient in and through the gels, respectively. The incorporation of NIPA grafted chains into NIPA gel makes the effective mesh size smaller and induces the additional friction between the probe-molecule and gel network. One may control the maximum mesh size of the NIPA gel and thus the effective diffusivity of a probe molecule within a gel by incorporating grafted chains and by adjusting the temperature.