ion reaction of O (3P) with Si2H6 has been studied theoretically. Two transition states of 3A and 3A symmetries have been located for this abstraction reaction. Geometries have been optimized at the UMP2 level with 6-311G+(d) basis set. G3MP2 has been used for the final single-point energy calculation. The rate constants have been calculated over a wide temperature range of 200~3000 K using canonical variational transition-state theory (CVT) with small curvature tunneling effect (SCT). The calculated CVT/SCT rate constants match well with the experimental value. ion transition of O (3P) with Si2H6 has been studied theoretically. Two transition states of 3A and 3A symmetries have been located for this abstraction reaction. Geometries have been optimized at the UMP2 level with 6-311G + (d) basis set. G3MP2 has has used for the final single-point energy calculation. The rate constants have been calculated over a wide temperature range of 200-3000 K using canonical variational transition-state theory (CVT) with small curvature tunneling effect (SCT). The calculated CVT / SCT rate constants match well with the experimental value.