As one kind of important lactic acid bacteria,Lactobacillus plantarum has attracted more and more attentions in the fields of food fermentation,industrial malolactic fermentation and healthcare. Semi-quantitative assay was used to explore the environmental factors which induced the biofilm formation by L. plantarum. Several different physical and chemical factors,and food additives were investigated and the results showed that strong positive biofilm formation by L. plantarum was obviously induced by 6% sodium chloride. Weak positive biofilm formation was induced by the weak acidic( pH 4. 8 ~ 5. 8) conditions,citrate and phosphate at the concentrations of 0. 2% and0. 4%,respectively,and the addition of gelatin. In conclusion,the biofilm formation by L. plantarum was greatly affected by some environmental factors.