¹Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing 210095, CHINA DOI : 10.9775/kvfd.2017.18999 The aim of this study was to determine the effect of applying three of lactic acid bacteria isolates AZZ1, AZZ4, AZZ7 and one commercial (CB) on the fermentation dynamics and aerobic stability of Napier grass silage. The grass was ensiled with or without the addition of a lactic acid bacteria inoculant at 1.0×106 CFU/g of fresh material to Napier grass silage. Napier grass was ensiled in laboratory silos and treated as follows: no additives (control), Pediococcus acidilactici (AZZ1), Lactobacillus plantarum subsp. plantarum (AZZ4), Lactobacillus plantarum subsp. argentoratensis (AZZ7) and Lactobacillus plantarum, Ecosyl MTD/1 (CB). To follow the fermentation dynamics during ensiling samples were taken on days 7, 14, 30, 60 and 90 of ensiling for chemical and microbiological analysis. Aerobic stability was determined on day 90 of ensiling. The experimental design was a completely randomized design, with a 5 × 5 × 3. The inoculant resulted in a more decreased (P<0.0001) in pH, water soluble carbohydrate, ammonia nitrogen, organic acid, aerobic bacteria and yeast, while a higher (P<0.0001) level of lactic acid content and lactic acid bacteria compared with control group. Treatment with AZZ4 had the better (P<0.0001) fermentation results. The aerobic stability of Napier silage was reduced with strains treatment compared with the control. In conclusion, the addition of bacteria inoculant resulted in better preservation and reduced the aerobic stability of silage. Keywords : Lactobacillus plantarum, Pediococcus acidilactici, Silage, Aerobic stability, Napier grass