Abstract: The function of Litopenaeus vannamei penaeidin-3 molecule for bacteria binding， protease activity inhibitory function and antibiosis were studied in this paper. The results showed that recombinant Lv-PEN-3 molecular could strongly bind bacteria， and inhibit secretary protease activity efficiently. But the antimicrobial function was much weaker. So the relevance among these three functions should be explored deeply.

Key words: Litopenaeus vannamei, penaeidin-3, bacteria binding function, protease activity inhibitory function