Japanese quail embryos were cultured by a plastic wrap technique after 2.5 days of normal incubation, and their development was investigated. Mean survival time was 13 days (2.5 days of preincubation plus 10.5 days of experimental culture). Mean morphological stage shown by the cultured embryos was Stage 28 of Zacchei (1961) (corresponding to 11 days of normal incubation) and the maximum stage of development was Stage 31 (corresponding to 14 days of normal incubation). In the latter half of incubation periods, cultured embryos showed retarded development, and their size was smaller than intact control embryos. Because continual observation of embryos is possible, this culture technique would be useful for experimental manipulation of the embryos or studies on lethal genes.