Intermolecular interaction energies of 14 orientation CHF3 dimers were calculated with electron correlation correction by the MP2 method. The cyclic C-2h dimer, which has two H/F contacts, has the largest interaction energy (- 1.63 kcal/mol). Electron correlation correction increases the attraction considerably, which indicates that the dispersion interaction is important for the attraction. The effects of electron correlation beyond MP2 are not large. Electrostatic interaction stabilizes the C-2h dimer significantly. The electrostatic energy (E-es) and the effect of electron correlation on the interaction energy (E-corr), which is mainly dispersion energy, of the Cyclic C-2h dimer at the potential minimum are -0.94 and -0.74 kcal/mol, respectively. The electrostatic interaction is highly orientation dependent, and thereby it mainly determines the orientation of the stable dimer. The dimers, which have short H/H contact, have large repulsive electrostatic interaction, and therefore the interaction energy potentials of these dimers; do not have minima. The H/H contact considerably destabilizes the dimer, while the short F/F contacts do not greatly destabilize the dimers. The calculated interaction energy of the CHF3 dimer is significantly larger than those of the CH4 and CF4 dimers (-0.44 and -0.69 kcal/mol, respectively). The large attractive electrostatic interaction is the cause of the substantially larger binding energy of the CHF3 dimer than the CH4 and CF4 dimers.