Abstract: By using 7-(2-hydroxyethoxy)-4-methylcoumarin(HEMC) hydrophobic modified hyaluronic acid (HA), photosensitive amphiphilic macromolecules(HA-HEMC) were prepared and HA-HEMC colloidal particles were obtained by self assembly.The structure and substitution degree of HA-HEMC were characterized by hydrogen nuclear magnetic spectra and UV-Vis spectrophotometer.The properties and morphologies of HA-HEMC colloidal particles were characterized by dynamic light scattering,nanoparticle size analyzer and transmission electron microscopy.Additionally,HA-HEMC colloidal particles were applied as the particulate emulsifier to stabilize oil-water interface and the emulsification performance of HA-HEMC colloidal particles in different conditions,such as mass concentration of colloidal particles,oil type,pH value and salt concentration in aqueous phase were investigated.Results showed that HA-HEMC were able to form spherical colloidal particles with the average diameter of 263 nm in selective solvent and HA-HEMC colloidal particles could stable oil-in-water Pickering emulsions in the broader range of pH(3~11) and various concentrations of NaCl.In addition,the colloidal particles were able to stabilize variety of oil-water system.