The properties of N, N-dialkyl chitosan monolayers and corresponding vesicles have been studied by LB technique and drug-release experiment. With increasing molecular weight of chitosan backbone and/or length of alkyl chain, both the compressibility and collapse pressure of N, N-dialkyl chitosan monolayer are enhanced. The experiments on drug-release behavior of N, N-dialkyl chitosan vesicles show that the drug-release rate and the equilibrium drug-release ratio are decreased with increasing the compressibility of corresponding monolayer. It is worth noticing that there is a linear relationship between the compressibility of N, N-dialkyl chitosan monolayers and the equilibrium drug-release ratio of the vesicles. (C) 2007 Elsevier Inc. All rights reserved.