By condensation of mitomycin C (MMC) with N-succinyl-chitosan (Suc-chitosan) and carboxymethyl-chitin (CM-chitin) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, Suc-chitosan-MMC conjugate (Sue-chitosan-MMC) and CM-chitin-MMC conjugate (CM-chitin-MMC) were prepared, respectively. The reaction conditions for 45 min at pH 5 and for 2 h at pH 5 were selected as the most appropriate for the preparations of Suc-chitosan-MMC and CM-chitin-MMC, respectively. Suc-chitosan-MMC was obtained as a water-insoluble product, while CM-chitin-MMC was partially water-soluble. When the ratio of MMC to the polymer supports changed in the conjugation reaction, the conjugates with 33% (w/w) and 23% (w/w) MMC contents were obtained as those most highly drug-loaded for Suc-chitosan-MMC and CM-chitin-MMC, respectively. At pH 7.4 at 37°C, Suc-chitosan-MMC regenerated MMC very slowly, while the release of MMC from CM-chitin-MMC was relatively fast. Each drug release followed very nearly pseudo-first order kinetics, in which the apparent drug release rate constants (k_apps) of Suc-chitosan-MMC and CM-chitin-MMC were 3.9×10^-3 and 1.1×10^-1 (h^-1), respectively.