In light of the great global interest in PAM as a source of active ingredients. So, it is important to investigate the impact of seasonal variation on Rosmarinus officinalis, Erica Multiflora and Cistus monspeliensis by evaluating of some biochemical responses in three sites Mount of Zaghouan (DZ), Mount of Mansour (DM) and Mount of Sarej (DS) and to compare their behavior in the three seasons (spring, summer and autumn).