Cobalt　phthalocyanine　(CoPc)　was　synthesized　and　self-assembled　on　the　surface　of　nanoscale　tin　dioxide　(SnO2)　by　in-situ　process,　marked　as　i,　and　Co-O　interaction　was　verified　to　conjugate　axially　between　macromolecule　(CoPc)　and　SnO2　in　CoPc/SnO2(i).　The　results　indicated　that　the　binding　constant　of　CoPc/SnO2(i)　was　two-order　higher　than　that　of　CoPc/SnO2(d)　synthesized　by　dipping　process,　marked　as　d,　while　the　numbers　of　binding　sites　were　comparable　in　both　samples.　The　degradation　rate　in　the　photocatalytic　activity　of　CoPc/SnO2(i)　was　32.5%　higher　than　that　of　CoPc/SnO2(d)　under　visible-light　irradiation　for　150　min　due　to　the　effective　electron　separation　and　energy　injection　from　LUMO　of　CoPc　to　conduction　band　of　SnO2　for　CoPc/SnO2(i)　based　on　the　strong　interaction　between　CoPc　and　SnO2.　The　degradation　recyclability　of　CoPc/SnO2(i)　retained　48.8%　in　10　times　under　the　same　circular　photocatalytic　process.　©　2008　Chinese　Chemical　Society　and　College　of　Chemistry　and　Molecular　Engineering,　Peking　University.