Objective To investigate the region fo r the epidemic area of tsutsug amushi disease. Methods Epidemiological studies, Orientia tsutsug amushi isolation, and preventive measures were used. Results The region belonged to epidemic area of south subtropical zone.The main host was found Rattus norvegicu.The main biological vector was Leptotrombidium deliens.The seaso nal trends of the quantity of Rattus no rveg icu and Leptotrombidium deliens w ere consistent with the incidence change of the disease in the region.Orientia tsutsug amushi has been isolated from Rattus norvegicu and Leptotrombidium deliens. Data showed that Orientia tsutsugamushi isolated strains mainly belong s to Karp.Sero-epidemiological data show ed that antibodies of Orientia tsutsugamushi are 100.0% positive in the residents of the regio n and 4.0% in army men.After taking comprehensive preventive measures, the incidence was descending. Conclusion Nan Peng Lie island w as proved an epidemic area of tsutsug amushi disease.