¹Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Muslim Indonesia, Makassar 90231, Indonesia DOI : 10.12991/jrp.2019.132 Glucosamine (GlcN) has great application in the food, cosmetic, pharmaceutical, and biomaterial areas; it is typically produced by hydrolysis in the exoskeletons of marine animals, one of the types of mud crab (Scylla serrata Forskal). Mud crab shells contain chitin and chitosan compounds which can be further derivatives for the production of GlcN HCl. The purpose of this study is to isolate and determine the level of GlcN HCl by hydrolysis of chitin and chitosan from mud crab shell. GlcN HCl was characterized by Fourier Transform Infra-Red (FT-IR) spectrophotometry, and its quantity was analyzed by UV-Vis spectrophotometry. Both methods used GlcN HCl as a standard for comparison and calculation of match factor (MF). The results of this study showed that the samples contain GlcN HCl either chitin or chitosan. FT-IR spectrum of chitin sample appears at wave number 1033 cm-1, 1532 cm-1, 3415 cm-1 whereas for chitosan at 1033 cm-1, 1532 cm-1, 3356 cm-1. Both sample spectrums showed vibration corresponding to ether (-O-), ethyl (CH2) and amine group (NH). The MF value of sample chitin and chitosan is 933 and 974, respectively; it shows that the resulting spectra are identical with the standard. The GlcN HCl level of sample chitin and chitosan was 553 and 993 mg/g, respectively. It can be concluded that the waste of mud crab shell has high potential as a natural source of GlcN HCl. Keywords : Chitin; chitosan; glucosamine HCl; mud crab shell