Abstract: The study was aimed to evaluate the characters of ereck milkvetch material and seek effective measures to improve its fermentation quality. The fresh and air basked ereck milkvetch was used. There were three treatments including water control （CK）, sucrose （2%） and formic acid （6 mL/kg）. The ereck milkvetch was fermented for 360 d in bags at RT. The results showed that the moisture content in ereck milkvetch silage dropped from 80% to 70% after air basking. Its pH value was increased significantly （P〈0.01）, but its content of lactic acid and ammonia nitrogen was reduced significantly （P0.01）. Compared with the CK, the formic acid and sucrose significantly reduced the pH value and ammonia nitrogen content （P0.01） but significantly increased lactic acid content（P〈0.05）. In addition, the sucrose significantly increased the contents of acetic acid, propanoic acid and nitrate content （P〈0.05）. Air basking and additives had no significant impact on dry matter content and recovery, but silage fermentation reduced nitrate content in ereck milkvetch by 70%-77% as well as nitrite content.