Phytogenic feed additives may be used as growth promoters in livestock due to its non-residue and non resistance and provide high-efficient healthy and nutritional food from the fields of animal cultivating and feeding. This paper reviewed their mechanism of in vitro activities of antibacterial and antioxidant and application research in the feed of swine and poultry and factors impacting efficiency of the phytogenic products as feed additives. ［Chinese Journal of Animal Nutrition, 2010，22（5）:1154-1164］