Pure polyteterafluoroethylene (PTFE) were prepared by using the process of cold pressure and sintering. A series of unaxial cyclic compression tests were carried out on solid cylindrical specimens of pure PTFE. The focus of study was to investigate time-dependent ratchetting behavior of PTFE under cyclic loading. It is shown that the stress-strain hysteresis loops exhibit pronounced nonlinearity with high stress range. The cyclic hardening is rate and stress range dependent. However, mean stresses have less effect on cyclic hardening than stress ranges. It is shown that viscoelasticity is obvious in the beginning cycles. The same stress range produces almost the same viscoelastic delay at the beginning of the compression cycles. A modified universal ratchetting model (URM), which is rate dependent is employed to predict the ratchetting strain under compressive cyclic loading condition at room temperature.