N-Succinyl chitosan (NSC) with various degrees of deacetylation (DD 6 – 94%) and substitution (DS 0.14 – 0.79) were successfully prepared from N-acetylchitosans in varying reaction time. Infrared spectroscopy (IR), 1H NMR and gel-permeation chromatographic (GPC) techniques were used to characterize their molecular structures. The moisture-absorption (Ra) and -retention (Rh) abilities of NSC are closely related to the DD and DS values. Under conditions of high relative humidity, the maximum Ra and Rh were obtained at DD values of about 50%, and when the DD value deviated from 50%, Ra and Rh decreased. Under dry conditions, when the DD value was 50%, the Rh was the lowest. The NSC with DS 0.65 to 0.79 exhibited better Rh than that of HA, and has the potential to prepare HA-like substances in pharmaceutical and cosmetics industries. Key words: Chitosan, moisture-absortion, moisture-retention and succinic anhydride.