A description is given of the synthesis and some properties of a new affinity-adsorbent — “trehalose-epoxy-activated Sepharose 6B” (TES). The chromatographic behavior on TES of acid α-glucosidase (AG) and of concanavalin A (CA) has been studied. Washed epoxy-activated Sepharose 6B (1 g) was stirred at 40°C with a solution of 2.27 g of α,α′-trehalose in 3 ml of 0.1 N NaOH for 16 h. The gel was washed with 100 ml of distilled water and was stirred with 3 ml of 1 M ethanolamine at 20°C for 16 h and the TES obtained was washed with water. When an unpurified extract of human liver or a purified AG preparation was chromatographed in several buffer systems and water, no adsorption of the enzyme on the TES was observed. CA biospecifically binds to TES and can be eluted quantitatively with 0.1 M methyl α-D-glucoside or D-glucose. Some aspects of the affinity chromatography of biopolymers having an affinity for α-D-glucopyranosyl residues on TES are discussed.