The calculated TST-CEQ state-selected reaction cross sections and rate constants forthe exchange reaction of H+ClH are reported.It is found that,although the collinear proba-bilities exhibit the oscillating behaviour,the TST-CEQ cross sections do not oscillate.Compa-rison of the different state-selected cross sections at a constant total energy indicates thattranslational energy is more effective than vibrational energy in promoting the reaction H+ClH.We also find that,the larger the vibrational quantum number of the reactant,the larger thereactive rate constant k~(TST-CEQ)(T,v)is at a given temperature.The state-selected rate constantsare then averaged to yield the thermal rate constants which are shown to be in good agreementwith our VTST calculations and those by Schwenke et al.. The calculated TST-CEQ state-selected reaction cross sections and rate constants forthe exchange reaction of H + ClH are reported. It is found that although the collinear proba- bilities exhibit the oscillating behavior, the TST-CEQ cross sections do not oscillate. Compa-rison of the different state-selected cross sections at a constant total energy that that transmissibility of energy is more effective than vibrational energy in promoting the reaction H + ClH. We also find that, the larger the vibrational quantum number of the reactant, the larger thereactive rate constant k ~ (TST-CEQ) (T, v) is at a given temperature. The state-selected rate constantsare then averaged to yield the thermal rate constants which are shown to be in good agreement with our VTST calculations and those by Schwenke et al ..