Chitosan depends on degree of deacetylation for its mechanical, biochemical and biological characteristics. Many methods are in literature for measuring the degree of deacetylation of chitosan compounds but none of them is universal and strong enough for all chitosan sources and preparation methods. First Derivative UV-visible (FDUV-VIS) and Fourier Transformed Infrared (FTIR) Spectroscopies are two of more common used techniques and have a lot of advantages comparing with other. The object of  the present review consists in listing some techniques, preparation forms, advantages and disadvantages of them taking into account specially  spectroscopy and facilitate relations between degree of deacetylation and other important properties.