Abstract:When the segments of etiolated mungbean hypocotyl were treated with IAA it was observed that the contents of CaM in tissue which were determined by ELISA and ethylene production were increased with increasing the concentration of IAA. The time course of CaM content change was also similar to that of ethylene production. Some inhibitors, including CPZ, TFP, and CHI, inhibited both increased ethylene production and CaM content by IAA treatment. The activity of ACC synthase and EFE were inhibited by CPZ. Both of IAA-induced ethylene production and CaM content were affected by the level of Ca in segments as a result of pretreatment with EGTA, CaCI2 and H2O before the experiment. From these results it was suggested that the Ca and CaM play an important role in induction of ethylene production inmungbean hypocotyl by IAA.