Abstract: The amphiphilic chitosan derivative N-succinyl-N'-decyl low degree of polymerization (DP) and narrow relative molecular weight distribution chitosan (SDLNCS20) was prepared from low DP and narrow molecular weight distribution chitosan (LNCS20, DP=20; Mw/Mn=1.20). Its structure was characterized by FTIR and 1HNMR. The solubility, emulsifying and wetting properties were also studied. Surface activity and critical micelle concentration (cmc) of SDLNCS20 were studied with the method of surface tension and fluorescence spectrum. The results showed the hydrophilic succinyl group and hydrophobic long alkyl chains were successfully introduced to the amine group of LNCS20. The cmc value of SDLNCS20 is 3.55×10-4 g•mL-1, and corresponding surface tension is 30.01 mN•m-1. Besides, SDLNCS20 was showed excellent water solubility and emulsifying property.