Gigaporous poly (styrene-divinylbenzene) (PS) microspheres have been effectively hydrophilized by coating with hydrophobically modified agarose (phenoxyl agarose, Agap). The effect of the phenoxy content on the amount of Agap adsorbed onto the PS surface was examined and various samples of microspheres, differing in surface Agap density, were prepared. After coating, the hydrophilicity of gigaporous PS microspheres was found to be greatly enhanced and the gigaporous character of PS microspheres was well maintained. The modified particles were further coupled with DEAE groups to prepare a DEAE anion exchange medium (DEAE-AP). A column packed with DEAE-AP showed low back pressure and high protein resolution at high flow velocity. Notably, the DEAE-AP column could completely separate a model protein mixture at a flow velocity of 3612 cm/h within 2 min. The results indicate that the gigaporous matrix has considerable advantages for high-speed protein chromatography.