Chicken Aminopeptidase H (APH) is an peptidase in the chicken sckeletal muscle,partially in charge of the production of flavor peptides and free amino acids after death stiffening.In this work,the gene of APH from chicken liver was expressed in E coli Rosetta(DE3),and the obtained recombinant APH (rAPH) was charaterized by SDS-PAGE,gel filtration chromatography and enzymatical analysis.The molecular weight of rAPH was found to be 52 KD and 369 KD by SDS-PAGE and gel filtration chromatography,indicating rAPH contains 8 or 7 subunits.