Polymorphism is the ability of a solid substance to crystallize into more than one different crystal structure. . Different polymorphs have different arrangements of atoms within the unit cell, and this can have a profound effect on the properties of the final crystallized compound. Repeatability in the energetic materials with transform Polymorphic could be in danger arises. Thus polymorphisms in a many compound as the energetic materials are used too much attention is located. Nitro groups can be different spatial arrangement on the nitrogen atoms in molecule Cl-20 depending on how its placement in the crystalline network Cl-20 different crystal forms provide. CL-20 can exist as four different polymorphic phases at ambient pressure and temperature α, β, γ and ε. The crystalline forms have different density and sensitivity that ε form because having more density and less sensitivity for military expenditure is more appropriate. In this paper various methods of preparation of CL-20 polymorphs and crystalline forms analyzed by using spectroscopic techniques, Raman, FTIR, UV, X.ray and XRD will be examined
