Photodissociation dynamics of acetaldehyde (CH3CHO) at 205 nm has been investigated by measuring laser induced fluorescence spectra of H (S-2) especially for the hydrogen atom production channels. The translational energy releases in the H + CH2CHO and H + CH3CO channels were measured from the Doppler broadened spectra, which are 156.9 +/- 13.0 and 113.8 +/- 10.0 kJ/mol, respectively. From the measured channel branching ratio and translational energy releases, it was concluded that the dissociation should take place on the triplet surface with considerable recombination barriers along the reaction coordinates. (c) 2006 Published by Elsevier B.V.