Abstract: Based on soil conditions in Henan province，physiologic characters and existing question in grass production，this paper conducted many applied studies about three trace element fertilizers（Zn、Mn and Mo）in Mixed Sowing grassland consisting of Birdsfoot(Lotus corniculatus L.) and Orchardgrass(Dectylis glomerata L.)，and analyzed applied ranges and concrete measures. The results showed that effective applied concentration of Zn fertilizer ranges from 200 to 600 mg/kg and optimum concentration ranges from 200 to 400 mg/kg which can promote grass photosynthesis and enhance seed yield, Combined Application of Zn, Mn and Mo can not only enhance photosynthetical ability and seed yield, but also promote forage production significantly (increasing by 11.8%) under the concentration of 200 mg/kg, 500 mg/kg and 300 mg/kg for Zn, Mn and Mo respectively.