The potential energy surface of the F+CHFO reaction is investigated at the MP2/6-311+G(d,p), MP4SDQ/ 6-311G(d,p), and QCISD(T)/6-311+G(3df,2p) (single-point) levels to explore the reaction mechanism. Theoretical calculations suggest that the hydrogen abstraction by fluorine atom leading to the products HF and CFO is kinetically much more competitive than the addition process. Furthermore, the direct dynamics calculation of this hydrogen abstraction reaction is performed at the QCISD/6-311+G(3df,2p)//MP4SDQ/6-311G(d,p) level. The rate constants are evaluated by means of canonical variational transition-state theory (CVT) including small-curvature tunneling (SCT) correction over a range of temperatures 220-1500 K. Our results agree well with the available experimental data. (C) 2003 Elsevier Science B.V. All rights reserved.