Hydrogels are three-dimensional polymer networks with high water absorption capacity. Regarding the medical application, biocompatibility and non-toxicity serve as essential requirements for hydrogels. Hydrogels are widely used in the development of smart drug delivery systems. The softness and hydrophilic nature of hydrogels make these compounds particularly suitable as modern drug delivery systems. Also the high porosity allows hydrogels to incorporate drugs into their gel matrix with controllable release properties. In this study, the purpose of making a hydrogel is to load and release the drug purposefully. First, the chitosan-dopamine hydrogel was prepared using inulin as the crosslinking agent, then the oxidized inulin was grafted to chitosan on one side and to dopamine on the other. Suitable analysis methods were utilized for the optimization of fabricated hydrogels with various crosslinking density. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal analysis, and elemental analysis were used to characterize the hydrogel. Also, the swelling capability, equilibrium water content, and degradation rate were evaluated, and then the loading and release of Indomethacin in the hydrogel were investigated. FTIR and elemental analysis confirmed the presence of inulin in the hydrogels network as well as interactions of chitosan with dopamine and inulin. SEM images also showed that the porosity decreased from 550±60 to 260±30 ?m as crosslinking density increased due to compression of the structure. Also, with increasing the crosslinking density, the rate of degradation, swelling and release of the drug decreased at all pH, and the highest rates of degradation, swelling and release of the drug were reported at acidic, alkaline and neutral pH, respectively. With increasing crosslinking factor, the degradation temperature of the samples increased. Also, hydrogels exhibited positive charge at acidic pH, negative charge at basic pH, and partially positive charge at neutral pH. These properties are related to the bi-functionality of dopamine and amine groups of chitosan which provide appropriated conditions to interact with drug with positive or negative charge. Also, as the crosslinking density increases, the porosity of the sample decreases due to more difficult access to the functional groups. The results showed that, with increasing percentage of crosslinking density, hydrogel degradation decreased from 42% to 31% in acidic environment after 7 days. Also, drug release after 6 hours in acidic environment was reported for the sample with the highest percentage of crosslinking density (sample 4) 33% and for the sample with the lowest percentage of crosslinking agent (sample 1) 75%. Also after 4 hours, the water absorption rate in the neutral medium was 1130% for the sample 4 and 1350% for the sample 1. Also, hydrogels had high adhesion to the tissue, even under wet conditions, which is due to the presence of catechol groups in the hydrogel structure, which increases the adhesion strength from 0.673 KPa to 0.740 KPa for sample 4, which has the highest percentage of crosslinking. Keywords: chitosan, drug delivery, crosslink inulin hydrogel, drug release, swelling, degradation