Abstract: Insect immune response to bacterial infection results in the synthesis ofantibacterial proteins in its hemolymph. This paper reviews the recent progress inthis field, concentrating on the characterization of the antibacterial proteins and the potential significance of these proteins. The most potent character of the inducible antibacterial proteins is that they have the capacity to identify foreign objects, to attack them and protect the insect itself from being injured. Other progresses related to the nature of these proteins, such as their molecular iology, are also mentioned.