We prepared antibodies from insect glycosaminoglycans (GAGs) and assayed the titer. Nine polyclonal antibodies against insect GAGs were raised for development of an ELISA in biological fluids (mice serum). The 3th booster collection of antiserum of BALB/c mice as a primarily antibody was assayed for titer determination by ELISA method. In sandwich ELISA of GAGs derived from Isaria sinclairii or other insects, antiserum from insect GAGs gave satisfactory results for so potent antibody(100: 1~1000:1) raising (manufacturing) agent in range of 10 ng/ml.