Photophysical and photochemical properties of C-60-pendant polymer in aqueous solution, in which C-60 was covalently incorporated into polymer cluster (C-60/unimer), have been studied by transient absorption spectroscopy. C-3(60)*/unimer was quenched by O-2 in two routes; the initial fast decay component was increased by addition of a detergent. From these observations, kinetic models for the quenching are proposed.