A　study　on　a　nano　anatase　TiO2　production　from　the　hydrolysis　of　TiCl4　was　presented.　In　the　nano　TiO2　suspending　medium,　the　photocatalytic　behaviors　for　some　organochlorine　pesticides　including　α,　β,　γ,　δ-BHC,　DDT,　dieldrin,　dicofol　and　agroceres　were　compared　and　studied　under　UV　irradiation　in　the　air.　Owing　to　structural　difference　of　C-Cl　in　the　molecule,　the　degradation　efficiencies　for　the　organochlorine　pesticides　presented　an　obvious　difference　with　the　order　of　dicofol　>　dieldrin　>　DDT　>　agroceres　and　α-BHC　>　γ-BHC　>　δ-BHC　>　β-BHC.　Accordingly,　the　nano　TiO2　material　was　applied　as　a　photocatalyzer,　which　catalyzed　transformation　of　organochlorine　pesticide　to　chlorine　ion.　Nanoparticle　of　silver　chloride　with　a　maximal　absorbance　at　the　wavelength　of　260　nm　were　prepared　in　the　surfactant　polyvinyl　alcohol　solution.　Organochlorine　pesticides　could　be　determined　according　to　the　concentration　of　silver　chloride.