This study was conducted to determine the optimum condition for the extraction of chitosan by using response surface methodology (RSM). The chitosan was extracted from the cockle shell (Anadara granosa). The extraction was optimized using five levels and five variables such as the concentrations of HCl (%), and its immersion time (hr), the concentration of NaOH (N), the deacetylation temperature (oC) and its deacetylation time (hr). The extraction process was involved three main steps which were, dimineralization, deproteination and deacetylation. A full factorial of central composite design by MINITAB software version 15 was employed to optimize the yield of chitosan. The optimum condition as predicted by the software was the concentration of HCl at 8% with 16.5 hours time of immersion, concentration of NaOH 2.6N, deacetylation temperature at 61oC, and 1.5 hours for deacetylation time. The determination of coefficient R2= 95.4 also was high, which means the experimental data was acceptable.