Abstract: The slime pulp, causing much trouble for the pulp and paper making industry, is usually produced by bacterium. Ten kinds of bacteria including N1, N2,…,N10 were screened from the slime hanging on the PM2 paper machine at UPM. They were identified as Sphingomonas azotifigens(N1, N3), Pseudomonas putrefaciens(N2), uncultured bacterium(N4), Filimonas lacunae (N5), Asticcacaulis excentricus(N6), Pseudomonas paucimobilis(N7), Siphonobacter aquaeclarae(N8), Sphingomonas pruni(N9), Flectobacillus Larkin(N10)through the morphological observation, physiological & chemical tests and 16S rRNA sequence analysis. Inoculate these bacteria to the simulative white water system and detect whether the slime was produced. It was proved that N5,N8,N10 were the key bacteria for the slime.