Two Haemaphysalis longicornis ticks were found positive in PCR assay of com-1 gene to detect Coxiella burnetii DNA from 100 ticks. The nucleotide sequences of com-1 and 16S rRNA gene were determined from 2 ticks and compared with those of other C. burnetii strains. The results suggest that H. longicornis harbor Coxiella sp. bacteria in Korea. Furthermore, icd, cbhE', and cbbE' genes are C. burnetii specific genes whereas com-1 gene is Coxiella genus specific gene. This study gives the first documentation to prove the existence of Coxiella sp. in tick collected in Korea.