To evaluate the ability of lactic acid bacteria (LAB) strains for making good quality silage in tropical regions, a silage fermentation model system was constructed by modifying a pouch method. Enterobacter sp. SG 1-1T and Saccharomyces cerevisiae SG 2-1Y, both isolated from Guinea grass silage,were used together with the LAB strain in the modified pouch method as typical silage coliform bacterium and yeast, respectively. For the silage material, autoclaved Napiergrass (Pennisetum purpureum Schumach.) was used. Two strains, LG 2-1 and N-22, used as model LAB strains grew well in this model system (modified pouch method) and their growth properties were strongly influenced by the inoculum size of each microorganism. From these results, this modified pouch method seems to be useful for the screening of LAB strains to make good quality silage in Thailand.