Most wrought magnesium alloys exhibit a significant tension-compression asymmetry in yield and work hardening behaviors. To some extent, the widespread implementation of wrought magnesium alloys is hindered due to this disadvantage in some special conditions. In this work, in order to quantitatively analyze the effects of the deformation mechanisms on the tension-compression asymmetry of wrought magnesium alloys, the plastic deformation behavior of the as-extruded ZK60 magnesium alloy under uniaxial tension and compression at room temperature is investigated by the crystal plasticity simulation and experimental methods. The crystal plasticity constitutive model including slip and twinning mechanism is established by modifying the viscoplastic self-consistent (VPSC) model. The activation and evolution of basal slip, prismatic slip, pyramidal slip, {1012}<1011> tensile twinning and {1011}<1012> compression twinning are quantitatively studied during the process of uniaxial tension and compression deformation. Tensile-compression asymmetry of the as-extruded ZK60 alloy with fiber texture is analyzed based on the microscopic plastic deformation mechanism. The results show that the tension and compression twinning in the axial tension-compression process are difficult to active, basal slip is the main deformation mode in the early stage of deformation, but the orientation factor of basal slip is low and has a hard orientation resulting in higher yield stress. With the rotation of grains, the critical shear stress of basal slip reduces, stress continues increasing and prismatic slip becomes the main deformation mechanism, moreover, pyramidal <c+a> slip also has a high activity. At this stage, the strain hardening rate is low and the stress-strain curve is smooth. In the early stage of compression, the tensile twinning has a high activity due to its low critical shear stress (CRSS), leading to a lower yield stress. The tensile twinning gradually saturated after the strain reaches 6.0%. And then, the relative activity decreases rapidly and the hardening rate increases at the same time. Since a large number of twin boundaries hindered the movement of dislocations, slip is no longer the major mechanism. In the later stage, the compression twinning startes activation and its relative activity rises rapidly, the accumulated stress during plastic deformation could be released and then the hardening rate decreases. It can be seen that, the variation in the relative activity of each deformation mode during compression deformation is much more complex than that during tension. The yield asymmetry and different work hardening behavior could be attributed to the combined effects of the strong fiber texture and the polar nature of twinning.