Abstract: Objective To establish an efficient and sensitive real-time PCR assay for the early detection of typhus group rickettsia based on the groEL gene. Methods MGB probe and specificity primers were designed based on the conserved sequences of groEL gene of R.provazakii and R.typhi and methodology evaluation were performed. Twenty six blood samples collected from probable patients with typhus were detected by the established assay. Results Twenty four non-typhus bacterial strains were tested. Specific amplification was only achieved with genomic DNA from R.provazakii and R.typhi. The lowest detection limit of the assay was about 100 copies of groEL genes. The average intra-and-inter coefficient of variations (CV) of the Ct value for different copies of groEL genes were 2.66% and 1.41% respectively. Two clinical blood samples from patients with typhus confirmed by seroconversion were detected as 103 copies/l and 102 copies /l respectively. Conclusion Real-time PCR assay was capable for detecting as few as 100 copies of groEL from genomic DNA and this assay is suitable to use in early diagnosis of R.provazakii and R.typhi infections.