By tensile and compressive tests of commercial pure titanium (CP-Ti), the tensile and compressive stress-strain relationships under various deformation tempretures and strain rates are obtained. Then, the influences of deformation tempreatures, tension/compression loading paths and strain rates on the stress-strain relationships are investigated. With Zener-Hollomon model, the influencing rules of the temperatures and strain rates on work hardening are obtained and the compressive deformation processing map is constructed. Based on the EBSD analysis, the grain orientations of CP-Ti are obtained and the plastic deformation mechanisms for tension and compression are clarified: the slipping dominates the tension plastic deformation and the mechanism of compression plastic deformation is dominated by slipping-twinning-slipping.