SUMMERY 1. The length of trypanosoma can be shown 17-25μ on the korean dairy cattles. 2. Crjthida of trypanosoma was is found out in depresed Tabanid flies head and about 60% in Tabanid flies head. 3. Trypanosoma in the tryptose blood agar base was variated afrer about 6 weeks. 4. Infectional rate of trypanosoma is same tate about 52%. 5. Mild production in multltlic infected dairy cattles is delow thbn non inflected daily cattes. and fat rate is about 3.1% in Holstein. 6. Injected trypanosoma rate in summer is higher than in winter about 10%. 7. Calfs in winter wasnot infected for trypanosoma. 8. Erythrocyte number decrease and Leucocyte number increase in a lot of infected trypanosoma of dairy cattles. 9. There is degeneration is genital organs. endocrine gland.