Two-year-old, full flower aohan alfalfa (Medicaga sativa cv. aohan) was chosen to evaluate the silage effect by using different additives of Qingbao Ⅱ , Caihe and Yishengkang. Result indicated that additives increased CP content (P＜0.05) and decreased CF, ADF and NDF content significantly (P＜0.05). Lactic acid content in additives treatments were significantly higher (P＜0.01) than control. These result showed that additives improved silage fermentation quality, reduced cellulose contents and improved silage nutritive value. Among three treatments, Caihe and Yishengkang were priority to Qingbao Ⅱ on the effect of promoting the desired lactic acid fermentation.