In order to identify the microorganism species on the backside paper of painting and calligraphy ( Nanjing Museum ) with the utilizing of the molecular biological method, the microbe on stain were isolated and identified.With the purpose of detecting whether the purely cultured microorganisms had the ability to degrade and damage paper, the cellulase activity, xylanase activity and protease activity were measured. A total of 11 bacterial strains and 5 fungi were gathered,9 bacterial strains and 2 fungi were identified,and they belonged to Bacillus,Alternaria and Trichoderma mainly. According to the results of enzymatic determination,as to the bacteria,the cellulase activity of Pantoea was maximum,the protease activity of Brevibacterium was maximum of 1. 76 U/mL and 6. 57 U/mL respectively.The protease activity of fungi was quite low,the cellulase activity and xylanase activity of Trichoderma were maximum of 17. 12 U/mL and 29. 01 U/mL respectively.The results are useful to develop the protective techniques to against the microbial erosion on paper culture relics.