After the surface treatment of filler particles with silane coupling agent (SCA), the network structure and the hairy chains expected to be formed by the trialkoxy and the dialkoxy SCAs, respectively. The relaxation behavior measured by ¹H pulse nuclear magnetic resonance (pulse NMR) showed that the network structure is rigid, whereas the hairy chain is flexible. The thermogravimetric (TG) analysis for the SCA-treated particles showed three-steps weight losses. Each step of was estimated as follows: The 1st-step is the evaporation of monomeric SCA without any interaction with surface. The 2nd-step is the physisorbed SCA formed hydrogen bonding with surface. The 3rd-step is the chemisorbed and physisorbed SCA oligomer and chemisorbed monomeric SCA. Pulse NMR and TG measurement were found to be useful for the characterization of SCA-treated layer.