The C-O bond cleavage from benzophenone substituted with 4-CH2OR (p-BPCH2OR, 1-3), such as p-phenoxymethylbenzophenone (1, R= C6H5) and p-methoxymethylbenzophenone (2, R= CH3), occurred by a stepwise two-photon excitation during two-color, two-laser flash photolysis. On the other hand, no C-O bond cleavage occurred from p-hydroxymethylbenzophenone (3, R = H). The first 355-nm laser excitation of 1-3 generates p-BPCH2OR in the lowest triplet excited state (T-1) which has an absorption at 532 nm. When p-BPCH2OR(T-1) is excited with the second 532-nm laser to p-BPCH2OR in the higher triplet excited state (T-1), the C-O bond cleavage occurred within the laser flash duration of 5 ns. The quantum yields of the C-O bond cleavage during the second 532-nm laser irradiation were found to be 0.015 +/-0.007 and 0.007 +/- 0.003 for 1 and 2, respectively. Although these values are low, the diminishing 1(T-1) or 2(T-1) was found to convert, in almost 100% yield, to phenoxyl (C6H5O.) and p-benzoylbenzyl (BPCH2.) radicals or methoxyl (CH3O.) and BPCH2. radicals, respectively. The T excitation energy, the energy barrier along the potential surface between the T states and product radicals, and delocalization of the T state molecular orbital including BP and CH2OR (R = C6H5, CH3, H) moieties are important factors for the occurrence of the C-O bond cleavage. It is found that the C-O bond cleavage and production of free radicals, such as BPCH2., C6H5O., and CH3O., can be performed by a stepwise two-photon excitation. The present study is an example in which the chemical reactions can be selectively initiated from the T-n state but not from the S-1 and T-1 states.