The effect of the functionallization of POMs on their properties was examined by the comparison between both titanium and its corresponding cyclopentadienyl subsituted polyoxocomplexes. The polarographic half wave potential of the complexes indicated that the effect of the functionallization of POMs increased the oxidizing ability of the polyoxoanions. The inhibitory effects of the CpTi polyoxocomplexes on tumor cells are higher than those of the corresponding titanium polyoxocomplexes, and the toxicity of the former is lower than that of the latter. The oxygenation reactions of cyclohexene, styrene, trans stilbene and maleic acid with PhIO or hydrogen peroxide(30% aqueous solution) catalyzed respectively by Ti and CpTi polyoxocomplexes were compared. The effect of the functionallization of POMs on their properties was examined by the comparison between both titanium and its corresponding cyclopentadienyl subsituted polyoxocomplexes. The polarographic half wave potential of the complexes indicates that the effect of the functionallization of POMs increased the oxidizing ability of the polyoxoanions. The inhibitory effects of the CpTi polyoxocomplexes on tumor cells are higher than those of titanium corresponding to polyoxometalates, and the toxicity of the former is lower than that of the latter. The oxygenation reactions of cyclohexene, styrene, trans stilbene and maleic acid with PhIO or hydrogen peroxide (30% aqueous solution) catalyzed respectively by Ti and CpTi polyoxocomplexes were compared.