The reaction of glucose with the berate ion has been studied in an anion exchange membrane. Two complexes, BL(-) and BL(2)(-), form in the membrane, and their corresponding stability coefficients beta(1)* and beta(2)* have been determined. The results have revealed that the BL(-) complex is much more stable in the membrane than BL(2)(-), and the stability coefficient beta(1)* varies as a function of the relative proportions of the berate ion and the BL(-) complex. The facilitated transport of glucose was performed through an anion exchange membrane by using the berate ion as carrier, the content of the latter was fixed by the concentration of boric acid in solution. The permeance of the membrane was measured in two cases. In the first case, the boric acid concentration was fixed and the concentration of glucose varied. In the second case, the glucose concentration was fixed and the influence of boric acid concentration was examined.