Abstract: Fourty-three of 1322 individuals studied at the forest area in Hei Longjiang province were confirmed as Lyme disease （LD）. Of these 43 cases, there were erythema chronicum migrans（ECM） in 23, facial palsy in 7, meningoencephalitis in 3, and arthritis in 10. Serum anti-B. burgdorferi antibody （BB Ab） was detected by ELISA. Three SD above the mean value in 124 healthy controls, 57mg/L for IgM Ab and 60mg/L for IgG Ab were set as the normal upper limits. In 124 healthy controls and in 54 patients not related to LD, none of the individual levels of both IgM and IgG anti-BB Ab were beyond the normal limite. In contrast, the levels of serum IgM or IgG or both were above normal in 95.6% （22/23） with ECM, 90% （9/10） with neurological disorders, and 100% （10/10） with arthritis. The results suggested that LD has been found in the area studied and that the anti-BB Ab test by ELISA was a highly specific and sensitive tool for diagnosing LD.