Abstract: Plants respond to herbivory through a series of physiological and biochemical defense mechanisms to counter the stress of herbivorous pests, including the dramatic changes in activities of various defense enzymes. Here, we reviewed the recent research progress on the response mechanisms of six common plant defense enzymes, SOD, CAT, POD, PPO, LOX and PAL, to insect stress, and compared their similarities and disparities. We sorted out their interactive sequences in response to the insect stress and analyzed the changes of defense enzyme activities and their associations with defense enzyme genes after being attacked by pests. Finally, we discussed the key problems/challenges in this area and proposed the prospects for studying the mechanisms of plant defense enzymes.