Emulsions　stabilized　by　polysaccharide/protein　complexes　have　attracted　great　interest.　However,　their　emulsion　properties　and　interfacial　viscoelastic　behavior　need　to　be　further　investigated.　Here,　emulsion　stabilized　by　chitosan/casein　complexes　was　used　as　a　model　system　and　the　effects　of　chitosan　concentration,　pH,　ionic　strength,　and　chitosan　deacetylation　degree　on　the　rheological　properties　and　stability　of　emulsion　were　studied.　The　presence　of　chitosan　could　effectively　improve　the　emulsification　activity　of　casein　and　the　stability　of　the　obtained　emulsion.　The　emulsion　stabilized　by　chitosan/casein　complexes　showed　broad　emulsification　pH　range　from　3.5　to　6.5.　The　rheological　properties　of　the　chitosan/casein　complexes　were　proved　to　be　primarily　affected　by　chitosan,　showing　great　shear　resistance,　fast　adsorption　interface　capability,　and　predominantly　viscous　characteristics.　The　loss　modulus　(G″)　was　much　larger　than　the　storage　modulus　(G′)　in　all　the　rheological　tests,　suggesting　that　the　stability　of　the　complexes　stabilized　emulsion　mostly　depended　on　the　viscosity　effects,　rapid　adsorption　characteristics　and　spatial　effects　of　biopolymer　structures.　These　findings　might　help　developing　stable,　controllable　polysaccharide/protein　emulsification　systems.　©　2020　Elsevier　Ltd