Ag/ZnO　heterostructure　nanocatalysts　with　Ag　content　of　1　wt　%　are　successfully　prepared　through　three　different　simple　methods,　where　chemical　reduction　and　photolysis　reaction　are　adopted　to　fabricate　the　heterostructure.　The　dispersity　of　Ag　clusters　and/or　nanoparticles　in　Ag/ZnO　nanocatalyst　is　investigated　by　EDX　mapping　and　XPS　techniques.　The　experimental　results　show　that　deposition-precipitation　is　an　efficient　method　to　synthesize　Ag/ZnO　nanocatalyst　with　highly　dispersed　Ag　clusters　and/or　nanoparticles;　the　photocatalytic　activity　of　Ag/ZnO　photocatalysts　mainly　depends　on　the　dispersity　of　metallic　Ag　in　Ag/ZnO　nanocatalyst;　the　higher　the　dispersity　of　metallic　Ag　in　Ag/ZnO　nanocatalyst　is,　the　higher　the　photocatalytic　activity　of　Ag/ZnO　photocatalyst　should　be.　In　addition,　it　is　also　found　that　the　dispersity　of　Ag/ZnO　photocatalyst　in　the　dye　solution　is　another　key　factor　for　liquid-phase　photocatalysis　due　to　the　UV-light　utilizing　efficiency.　The　higher　the　UV-light　utilizing　efficiency　is,　the　higher　the　photocatalytic　activity　of　Ag/ZnO　heterostructure　photocatalyst　should　be.　©　2008　American　Chemical　Society.