This study examined the production of chick-quail chimera by transfer of blastoderm cells and investigated the developmental pattern of chick blastoderm cells in the quail subgetminal cavity. To produce the chick-quail chimera, 1,500 to 2,000 cells of chick embryos in the blastodermal stage were microinjected into the subgerminal cavity of quail embryos. The presence of the blastoderm cells of chicks in the subgenninal cavity of quail embryos was detected by Feulgen staining. The developmental pattern of the blastodenn cell division of chicks in the quail subgerminal cavity was examined by chromosomal analysis. When quail embryos which were injected with chick blastoderm cells were cultured in surrogate egg-shells, average hatchabilities were 40.0% for the wild type and 45.8% for the black type. A chick-quail chimera was produced from the black type. After the blastoderm cells of chicken embryos were itgected into the subgeminal cavity of quail embryos, the presence of blastoderm cells of chicken embryos was detected by Feulgen staining in the ectoderm, endoderm, and mesoderm of the subgetminal cavity of quail embryos. When the blastoderm cells of chicken embryos were injected into the subgemunal cavity of quail embryos, the chromosomal analysis revealed that the occurrence of blastoderm cell division of chicken embryos was exxremely rare.