Properties of materials are rather interesting under pressure, and much attention has been paid to structural transition induced by pressure. Here the high-pressure behavior of CF 4 has been investigated between 0 and 150GPa using the first-principles methods. Two structures with C2/c and P2 1 /c symmetries are stable at 0–4.8 and 4.8–22.1GPa. The lattice parameters agree with the experimental results. Besides, another low-enthalpy structure with space group I4¯2m is favored above 108.3GPa. Phonon calculations also confirm its dynamical stability. This new high pressure phase of CF 4 may therefore stimulate the experimental work. The electronic structures indicate that CF 4 is a molecular solid under very high pressure.