Novel amphiphilic chitosan derivative of N,N-dimethylhexadecyl carboxymethyl chitosan (DCMCs) was synthesised. The physical properties of DCMCs were characterised by Fourier transform-infrared spectroscopy, nuclear magnetic resonance spectroscopy, X-ray diffraction and differential scanning calorimetry. DCMCs can form core–shell micelles with low critical micelle concentration (31 mg L−1). The core–shell micelles exhibited spherical shape with positive charge (+50.7 mV) and narrow size distribution (polydispersity index