This research was done to study of Feeding roughage spoiled with Pb to the population of rumen microbes in vitro. This research was held from 8 June to 14* June 2009 in Animal Feed and Nutrition Laboratory Agriculture Faculty of Sriwijaya University. This research was done with 4 treatment (R0, RI, R2 and parameters: 1). PopulationR3) with 4 replication were done to observed amylolytic bacteria…