To determine differential gene expression profiles in the salivary gland of a predatory flower bug species, Orius laevigatus Fieber, a subtractive cDNA library was constructed by suppression subtractive hybridization. The major transcripts encoding trypsins (28.6% of the total ESTs) were eliminated from the library and then remaining salivary gland-specific genes were searched. A total of 513 expressed sequence tags (ESTs) were clustered and assembled into 129 contigs (64 multiple sequences and 65 singletons). About 58% were matched with insect genes. In total, 38 genes (179 ESTs) were found from the library by BLASTx search. A hemolysin-like protein occupied ca. 8% (41 ESTs) of the library. Hemolysin is known to destruct cells including blood cells by forming pores on the cell membrane. A hemolysin-like salivary protein of O. laevigatus might be hemolytic against the prey cells, thereby allowing O. laevigatus to facilitate feeding. Several contigs encoding lipase was also identified from the salivary gland-specific library. Discovery of salivary gland-specific genes should promote further studies on biologically active components in the saliva of O. laevigatus.