b -cyclodextrin (CD) penetration into the lumen of a -Hemolysin and Maltoporin channels is seen as a transient drop in ionic current due to the partial occlusion of the channel pore. By varying the solution osmotic pressure with different salt species and their concentrations, we probe the properties of the water of hydration and the interactions of different salts with both CD and the channel. We find that the binding not only involves dehydration but can also be accompanied by significant conformational changes in CD molecule. When CD interacts with Maltoporin channel, its association with the channel pore is apparently strong enough to induce lateral deformation of CD molecule [Manuscripts in preparation].