The quantum yield of triplet formation (φISC) and the triplet lifetime (τT) of C 60 , as well as the quantum yield of singlet oxygen formation (φΔ) by the quenching of the triplet state of C60 and the singlet lifetime (τ0) of oxygen are measured by a time resolved thermal lensing technique. Both φISC and φΔ are nearly unity and the lifetimes of both the triplet C60 and the singlet oxygen are in the range of 8￣60 μs and 20 μs respectively.