Alpha-amylase was immobilized into photographic gelatin by chemical cross-linking with chromium (III) acetate and chromium (III) sulphate. Cellulose triacetate film strips, enabled simple handling when coated with an alpha-amylase-gelatin mixture, accomplishing a high degree of durability during consecutive immersions into reaction media. The optimum conditions for pH, substrate concentration, temperature, incubation time and storing conditions of free and immobilized alpha-amylase were determined. The effect of use number on activity and the effect of resting on reuse number were also determined. Photographic gelatin was found to be a very efficient natural polymer, due to its extraordinary diffusion characteristics for immobilization as a carrier.