Abstract: In course of silage fermentation, different kinds of Lactobacillus have different capability to produce lactic acid ancl also produce different baeteriostasis and aromatic material. In the past few years, some studies show that actie acid and other aromatic components are produced during the fermentation of silage with Lactobacillus. These components have great effects on quality of silage. Bacterioeine and other bacteriostasis material are also produced and they inhibit the growth of harmful microorganisms. The article reviews recent advance in metabolism of Lactobacillus and its effects on quality of silage.