[Objective] The study aims to isolate and identify xylan-degradation bacteria from the gut of a fungus-growing termite——Macrotermes barneyi. [Methods] Using an oligotrophic medium containing birchwood xylan as the only carbon source and Congo red activity staining method, we obtained a xylan-degradation bacteria based on the transparent zone around the clone and the bacteria was identified by microscope morphology, Gram-staining and 16S rRNA gene sequence analysis. To learn the distribution of the xylanase, cell growth curve and xylanase assay of intercellular and extracellular activities were investigated using DNS method. [Results] The xylan-degradation strain, isolated from the gut of M. barneyi, was named as Paenibacillus sp. Mb1. The strain grew to a high level at 72 h. Paenibacillus sp. Mb1 secreted extracellular xylanase at a rapid rate in the exponential phase, and reached to the maximal xylanase production at 96 h, then kept steady until the end of Mb1 cultivation. [Conclusion] Paenibacillus sp. Mb1 with high xylanolytic activity have been isolated from the hindgut of M. barneyi. It might be a good candidate strain in studying termite xylan degradation and biomass conversion.