Peanut belongs to the genus 1 species of Leguminosae, commonly known as peanut. There are about 20 species in this genus, which are generally believed to be native to eastern South America and introduced to China in16th century. Peanut originated in Brazil and is now widely introduced all over the world. In 2007, confirmed by experts from Xi 'an Wenbao Center, peanuts had appeared in the crops unearthed from the graves of Hanyang Mausoleum 2 100 years ago.