Abstract: The tobacco calli were cultured on MS medium contained 5 mmol/L coffeic acid (CA) and/or 10 mmol/L CoCl2 (inhibitor of ethylene synthesis) in dark(25±2 ℃), while methyl jasmonate (MJ, about 1ml/15g FW) were sprayed to the calli. Two days after treatment, the contents of ethylene, salicylic acid (SA) and pathogen related protein (PRP), as well as the activities of phenylalanine ammonia-lyase(PAL),β1,3-glucanase and chitinase(endo-, exo-) were determined. MJ significantly increased the contents of ethylene, SA and PRP and the activities of PAL, β1 ,3-glucanse and chitinase. CA inhibited ethylene and salicylic acid production inducing by methyl jasmonate,CoCl2 inhibited ethylene production, but did not inhibit SA production inducing by methyl jasmonate. Both CA and CoCl2 have coordinate role with MJ to increase the activity of PAL, but they inhibited the role of MJ for increasing β1,3-glucanase activity. CA markedly inhibited the in duced role of MJ for increasing endochitinase but almost inhibited the exochitinase activity. CoCl2 have little effect on endochitinase activity, but increase dexochitinase activity.The results show that there are different pathways of signal transduction in induced different resistance enzymes and PRP.SA plays a main role and ethylene plays a minor role in those enzymes and PRP induced by MJ.MJ may be the upper molecule of SA and ethylene in signal transduction.