Effects of anisotropy on the microstructural characteristics and mechanical behavior of shock loaded of AZ31 magnesium alloy have been investigated. Using electron backscatter diffraction, tension twinning was observed in both shock loading directions along the normal (ND) and rolling directions (RD). Compression tests were carried out along ND and RD in both as-received and post-shock conditions. It indicated that the RD samples show a more notable hardening behavior compared to the as-received conditions. Moreover, it is postulated here that detwinning results in a drop of strain-hardening rate for the ND samples under post shock reload conditions and tension twinning formed during the shock wave loading process leads to a signiﬁcant moving left of the peak strain hardening rate for the RD samples under post shock reload conditions.