Since the reservoir of leptospires organism is consisted of a broad spectrum of animals, the best method of prevention is vaccination. The clinical trial of leptospires vaccine conducted on human volunteer for its immunogenicity and safety. Summarized results are as following : 1. The Oral temperature among vaccinated group ranged from $36.7{pm}0.46^{circ}C;to;37.0{pm}0.34^{circ}C$, while in placebo injected group it ranged from $36.4{pm}0.46^{circ}C;to;36.7{pm}0.53^{circ}C$. There was no association between vaccination and fever (p>0.05) 2. Mild local reactions revealed in vaccinees were swelling (50-75% ), Redness($75{sim}90%$), and induration ($25{sim}40%$). Placebo injected group revealed only redness in 12.5% in 1st injection and 37.5% in second injection. The duration local reactions on injection site for th vaccinees and place groups disappeared within 48 hours. 3. Generalized Symptoms complained by the vaccinees were myalgia (25%), back pain(15%), headache (15%), pruritus(15%), and abdominal pain(10%), whereas placebo group complained of headache (25%), myalgia(12.5%), back pain(12.5%), pain in eyes(12.5%), abdominal pain(12.5%) pruritus (12.5%) and nausea(12.5%). 4. The serological test(MAT) of vaccinees showed geometric mean antibody titer as follows : a. L. icterohemorrhagiae lai 1 week after 1st vaccination : 22.45 1 week after 2nd vaccination : 111.23 3 week after 2nd vaccination : 266.64 b. L. canicola canicola 1 week after 1st vaccination : 24.62 1 week after 2nd vaccination : 123.92 3 week after 2nd vaccination : 276.55 c. L. icterohemorrhagiae copenhageni 1 week after 1st vaccination : 28.28 1 week after 2nd vaccination : 128.55 3 week after 2nd vaccination : 247.88 Whereas all of the place injected group showed below 1:20 titers. The sero-conversion rate of vaccinees were 100 percent.