The　meso-tetraphenylporphyrinatozinc/titanium　dioxide　(ZnTPP/TiO2)　nanocompounds　with　different　molar　ratios　were　synthesized　by　sol-gel　method　at　400　degrees　C,　4h　The　nanocompounds　were　characterized　by　XRD,　UV-Vis,　FTIR　and　Fluorescence　methods.　Anatase　for　TiO2　in　the　nanocompounds　was　defined,　and　ZnTPP　was　also　obtained　during　in-situ　process.　Photocatalystic　activities　of　them　influenced　by　the　proportion　between　ZnTPP　and　TiO2　were　discussed　under　visible　light.　The　results　show　that　a　nanocompound　(ZnTPP　:　TiO2　=　1　:　100　mol%)　has　the　best　photocatalystic　activity,　and　the　degradation　of　Rhodanmine　B　is　up　to　92%　after　150　minutes　under　visible　light　irradiation.　The　sensitization　mechanism　is　that　the　photogenerated　charge　carriers　are　separated　by　Zn-O　bond　between　ZnTPP　and　TiO2.