Chitin, a linked by β(1→4) bonds, is the main component in the cuticles of crustaceas, insects, and mollusks and in the cell walls of some microorganisms. In the nature, three different crystalline polymorphic forms of chitin exit under natural conditions. These forms differ in the packing and polarity of the GlcNAc chains. The most abundant, α-chitin, where chains are anitiparral, is present in arthropods, fungi and cysts of Entamoeba; β-chitin, made of parrallel chains. has been identified in the pen of the squid Loligo. In the third form, γ-chitin, two chains would run in one direction, and another in the opposite direction. This form has been reported in cocoon fibers of the beetle ptinus and the stomach of Loligo. In this study, α, β, γ-chitin was isolated from crab shell, squid pen, and beetles of cuticles by treatment with dilute NaOH solution for deprotenization, followed by treatment with dilute HCl solution for demineralization, and physicochemical properties investigated.