Abstract: A process for preparing a wide-pore adsorbent adapted for use in chromatography, comprising mixing fine disperse non-porous silica having a specific surface area S of 35 to 380 m.sup.2 /g with water followed by drying the aqueous suspension at a temperature within the range of 100.degree. to 450.degree.C to give a silica xerogel and particulating thereof. The xerogel, prior to the particulation or thereafter, is subjected to the hydrothermal treatment in an autoclave at a temperature within the range of from 100.degree. to 380.degree.C and under a pressure of 1 to 300 atm., followed by drying at a temperature of 100.degree. to 300.degree.C.The above-described process enables the preparation of an adsorbent with larger pores as compared to adsorbents prepared from fine disperse non-porous silica and produced by conventional processes. The process according to the present invention makes it possible to produce an adsorbent having a specific surface area within the range of from 2 to 280 m.sup.