The intermixing of fluidizing gas between the compartments of a compartmented circulating gas fluidized bed fitted with a V-valve and riser combination has been experimentally studied. The intermixing of fluidizing gas that flows co-current (cross flow) as well as counter-current (back flow) to the circulating solids has been investigated. At low aerations, gas cross flow increased proportionally with the increase in solid circulation rare. But at high aerations, gas cross flow increased with aeration even when solid circulation decreased. Studies on back flow of gas revealed some interesting observations, At high fluidizing bed height on upstream side back flow of V-valve, gas has been negligible, But at low upstream bed heights and low aeration in V-valve and riser back flow of V-valve, gas has been substantial.