The UV photodissociation dynamics of OCS starting from the bending excited (010) state was compared to that from the ground vibrational state (000). The rotational distribution of CO(X-1 Sigma(+)) was measured by (2 + 1) resonance enhanced multiphoton ionization, in which dissociations from the two different initial states were discriminated from the translational energies of the CO fragments. Quantitative analysis revealed that the non-adiabatic transition probability in dissociation starting from (010) was 0.21 that is similar to but slightly smaller than the value. 0.34, from (000). (C) 2002 Elsevier Science B.V. All rights reserved.