Specific high titre antisera to TSH were raised in two sheeps injected with 100μg (booster injection. 50μg) highly purified TSH preparation by the multi-site intradermal immunization technique. Blood were bled at two week intervals by cardiac puncture without killing the animals and solution of anti-anemia drug was given to sheeps after each leting blood. The antisera were monitored by TSH RIA Kit. Titres were range from 28×10⁴ to 205×10⁴ and no cross-reaction occured between TSH antisera and human LH, FSH, HCG and all antisera have the avidity more than 10¹⁰L/mol.