The development of radioimmunoassay (RIA) for high-density lipoprotein (HDL) in Japanese quail serum will contribute to the screening of drugs acting on cholesterol transport. We have developed a double antibody RIA method for J. quail HDL. The first antibody was raised in rabbit by immunization of HDL isolated by the dextrane sulfate-$Mn^{#}$ precipitation method. For the preparation of raclioiodinated antigen, HDL was further purified by combination of electrophoretic procedure. Using the second antibody raised in goat by rabbit IgG, we have furnished the RIA method for HDL. It showed high specificity and sensitivity of working assay range, 0.1-33.mu.g HDL/tube. There was no correlation between the radioimmunoassay of HDL and the enzyme assay of HDL-cholesterol.