he functionality of antioxidants in dietary sources is introduced and their antioxidant properties reviewed. Application of natural plant extracts, including Mesona procumbens Hemsl. (Hsian-tsao), Antrodia camphorata, Eucommia ulmoides Oliv. (Du-Zhong), tea seed (Camellia oleifera Abel.) oil, soy-based food extracts, fruit extract from Artocarpus heterophyllus, root extract from Alpinia pricei Hayata, and mulberry (Morus atropurpurea Roxb.), and Cassia tea (Cassia tora L.) is also summarized. This chapter also provides a commentary and future trends for the natural plant extracts or their active compounds as food antioxidants.