Many methods can by used for the quantitative determination of the three types of immu-noglobulin. On the basis of the single radial immuno-diffusion method used by John L. Fahey,certain modifications have been made on the methods of diluting standard solutions and theirconcentrations, and the standard concentration of the immunoglobulins and the antibody-con-taining agar diffusion plates. In order to find the optimum condition of cultivation, theeffects of various temperatures and various cultivation time given by G. Mancini et al havebeen checked, and satisfactory standard curves have been obtained. Therefore, the accuracyof the analytical results is guaranteed. According to the results obtained, there is no observable effect on the diameter of theprecipitating ring when the temperature in culture-box is 35?C to 40?C and the cultivationtime extends to 96 hrs.