Brassicanapuswas the third leading source of vegetable oil in the world after only soya bean and oil palm.The development of expressed sequence tags (ESTs) for B.napus cDNA libraries, and their public deposition, has generated a rich resource for protein discovery, thereby providing an opportunity for better understanding of the potential antimicrobial peptides (AMPs) gene resources of B.napus.In the present work a general search aiming to identify antimicrobial peptides was carried out on the three different B.napus EST Databases: 136202 and 35788 ESTs generated from seeds and leaf of B.napus,and 644998 ESTs of B.napus download from the EST database of GenBank respectively, which formed 201200unigenes.