Abstract: In this study, degradated and hydrophilized larch tannin was used to prepare water soluble chelates with iron, mangnese, zinc and copper ions. The application test of these chelates, as micronurtient, was successful to increase 19.8%25.4% apple and 26.5% Ginkgo biloba leaf production. As ligand of the chelate, larch tannin is an abundant natural resource, available in low price, and possesses good compactibility with plants, which can be used as substituent of the traditional EDTA for preparing chelated micronutrients.