Abstract: The reaction dynamics of yttrium atoms with sulfur dioxide molecules at a high collision energy of 36 kcal/mol was studied using time-sliced velocity map ion imaging, crossed molecular beam and laser-ablation method. The product YO was detected via multiphoton ionization at various wavelengths in the region of 482 - 615 nm. The slice images of YO show a broad velocity distribution and forward-backward peaking angular distribution. The forward scattering signal is stronger than its backward distribution. This indicates that the reaction proceeds via an intermediate complex and the lifetime of the intermediate state is less than one rotational period. The formation of complex suggests that electron transfer occurs in the oxidation reaction.