Ag/Ag4V2O7　nanocomposites　with　Ag　nanoparticles　supported　on　Ag4V2O7　nanorods　have　been　synthesized　with　the　assistance　of　sodium　dodecyl　sulfate　(abbreviated　to　SDS)　by　a　facile　one-step　hydrothermal　reaction　and　exhibit　high　photoelectrochemical　response.　Ag4V2O7　nanorods　are　pointed　at　both　ends　with　an　average　width　of　ca.　200　nm.　Ag　nanoparticles　are　formed　in　situ　on　the　surfaces　of　the　Ag4V2O7　nanorods.　The　crystal　structures　and　morphologies　of　the　samples　are　affected　significantly　by　the　SDS　concentration　and　hydrothermal　reaction　time.　The　possible　crystal　growth　process　of　Ag/Ag4V2O7　nanocomposites　induced　by　SDS　has　been　discussed　preliminarily.