Several analytical techniques, including High Performance Liquid Chromatography (HPLC) and Spectrophotometry, were developed to quantify the chitosan content in water-soluble fertilizers, with a focus on optimizing the hydrolysis conditions for chitosan. The results showed that the optimal hydrolysis was found to occur using a 1+1 hydrochloric acid solution at 100°C for 24 hours. For HPLC, using 1-phenyl-3-methyl-5-pyrazolone (PMP) as the derivatizing agent, the method exhibited a linear range of 1-200 mg/L, a detection limit of 0.07 mg/L, and a spiked recovery rate of 95%-101%.    Spectrophotometry, on the other hand, had a linear range of 0-100 μg, a detection limit of 0.47 μg, and a recovery rate of 94%. The two methods demonstrated good agreement in their determination of chitosan content in water-soluble fertilizer samples, satisfying the analytical requirements for chitosan in such fertilizers. HPLC proved to be more efficient with fewer interference factors. Additionally, the use of methyl fluorene chloroformate (FMOC-Cl) as a derivatizing agent for chitosan hydrolysate, followed by detection with HPLC, yielded results that were essentially consistent with the previous two methods. However, the HPLC and spectrophotometry methods established in this study were not suitable for determining chitosan content in water-soluble fertilizers that contain nitrates.