[Objectives]  To investigate the characteristics of the pathogen responsible for some termites developing a red head before they die. [Methods]  A bacterial strain was isolated from termites with red heads, cultured and purified and identified using micromorphology, Gram staining and 16S rRNA gene sequence analysis. The conditions under which this bacterial strain produces red pigment and its fermentation products were investigated using liquid chromotography and mass spectometry. [Results]  The termite was identified as Reticulitermes speratus and a red pigment-producing Gram-negative bacterium RS was isolated from the head of this species. 16S rDNA sequence analysis identified this bacterial strain as Serratia marcescens. The RS strain is, however, different from most other S. marcescens. It continues to produce red pigment, identified by HPLC as prodigiosin, at 37 ℃. [Conclusion]  This study is the first to isolate and purify a prodigiosin-producing S. Marcescens RS from R. speratus, which lays a foundation for further research on the biocontrol of termites and the production of prodigiosin.