We have carried out quasi-classical trajectory calculations for the title reaction. The effect of initial ro-vibratioanl state of HCl on the stereodynamics of O( 3 P)+HCl→OH+Cl reaction on 3 A″ potential energy surface was investigated. Integral cross sections, product ro-vibrational state distributions, differential cross sections, and three angle distribution functions about the products alignment and orientation have been presented. The results manifest that the vibrational excitation has a larger influence on the total cross section, differential cross section, angle distributions (concerning the initial/final velocity vector, and the product rotational momentum vector) compared with the rotational excitation, and the phenomena are quite different with the increase of the vibrational and rotational quantum number. Also the products are vibrationally cold and rotationally hot.