This experiment was to investigate the Leptospiral antibody in the pigs with the serological test in two areas of Kangwondo from March to April. 1989. Twelve different living antigen (L. icterohaemorrhagiae, L. pomona, L. hardjo, L. australis, L. canicola, L. autumnalis, L. grippotyphosa, L. tarassovi, L. pyrogenes, L. bataviae, L. lai and L. ballum) of Leptospira interrogans was used for the serological test in the pigs. The blood sample of 280 pigs collected from the slaughter houses were detected by microscopic-agg-lutination test. The results were as follows, 1. Among the serum sample of 280 heads of the pigs, 6 heads of the swine (2.14%) were positive. 2. Among the positive sample of 6 heads, 3 heads of the swine (1.1%) showed the antibody of L. ict-erohaemorrhagiae, 2 heads of the swine (0.7%) showed the antibody of L. canicola, and 1 head of the swine (0.4%) showed the antibody of L. pomona. 3. The positive rate of Leptospira interrogans in the swine of Kangwondo appeared to be very low.