The state-to-state integral cross sections of the Cl + HCD3(v) -> HCl(v') + CD3 reaction have been studied experimentally and theoretically. Reactions involving both Cl(P-2(3/2)) and Cl(P-2(1/2)) were analysed. In the experiment, a time-sliced velocity imaging detection method under crossed-beam condition was used. For theoretical study, a multiple potential energy surface model is employed. A combined reduced dimensionality quantum dynamics and quantum chemistry method is used with explicit treatment of spin-orbit coupling. Good agreement between experiment and theory is obtained, especially for the energy threshold dependence of the cross sections. (C) 2013 Elsevier B. V. All rights reserved.