Cellulase-secreting microorganisms include fungi and a few cellulose-decomposing bacteria.In this study,human rectal microbiota were screened by using filter paper as the only carbon source,and one cellulase-secreting bacteria,H1,was successfully separated.Its cellulase-secreting activity was identified using cellulose congo-red medium,morphology identification undertaken by gram staining,and classification accomplished via molecular identification.The cellulase activity of H1 was also analyzed.The results show it is positive in the cellulose congo-red medium,short and rod-shaped and gram-negative.Cellulase activity analysis indicated that its highest cellulase activity is about 0.8 U occurred at 13 hours.Molecular identification characterized the strain as Pseudomonas specie.