The initiation condition for deformation mechanism of extrusion AZ60 Mg alloy during tensile deformation along different directions at room temperature was investigated through experiments and visco-plastic self-consistent (VPSC) modeling, and the relationship between the deformation mechanism with the flow curves, texture evolutions, and microstructure of ZK60 Mg alloys was also analyzed. By adjusting the parameters in VPSC model, the crystal plastic mechanics model with slip coupled with twin was established. The differences in texture evolution during tension along different directions were compared, and the influence of deformation mechanism on the yield asymmetry was analyzed. The experiment and simulation results show that due to the initiation of {102} twin, most grains are rotated at a large angle (about 90°) when the tensile direction is perpendicular to the extrusion direction, namely PED. The prismatic <a> slip is the main deformation mode resulting in the yield asymmetry of ZK60 alloy during tensile deformation along different directions. When the ZK60 alloys are under tensile deformation along extrusion direction (ED), due to the preferential orientation, the {101} twin is difficult to initiate and the higher yield strength can be obtained. The yield stress under tension along the direction with an angle of 45° to ED is higher than along PED. As the tensile stress gradually increases, the prismatic <a> slip is gradually initiated, resulting in the higher stress curves along PED than those along the direction with an angle of 45° to ED.