In the present study we reported the extraction of low cost chitosan's (CHS1, CHS2, CHS3 and CHS4) from shrimp shells by extraction of chitin, then alkaline deacetylation of chitin with strong alkaline solution at different period of time. The different prepared chitosan's (CHS1, CHS2, CHS3 and CHS4) were characterized by FTIR spectroscopy, thermal stability, morphology, crystallography, elemental analysis and degree of deacetylation . The data showed that the prepared chitosan CHS2 has the most thermal stability and the highest degree of deacetylation. Keywords: Chitosan, Hydrogyl, Shrimp shells, Chitin, Morphology. In the present study we reported the extraction of low cost chitosan's (CHS1, CHS2, CHS3 and CHS4) from shrimp shells by extraction of chitin, then alkaline deacetylation of chitin with strong alkaline solution at different period of time. The different prepared chitosan's (CHS1, CHS2, CHS3 and CHS4) were characterized by FTIR spectroscopy, thermal stability, morphology, crystallography, elemental analysis and degree of deacetylation . The data showed that the prepared chitosan CHS2 has the most thermal stability and the highest degree of deacetylation.