Studies on development in vitro of excised ovaries in the sibmate of diploid Brassica campertris L. ssp. chinensis (L.) Makino cv. Seppaku-taina and in the sibmate of autotetraploid Brassica calprpestris L. ssp. pekileensis (Lour.) Olsson cv, Nozaki-hakusai were carried out. Development in vitro of ovaries excised at fcur days after pollination was studied in various culture media, temprature and light intensities. Results obtained were as follows. (1) Seed set in the capsules and percentage of germnated seeds in diploid Seppaku-taina were higher in each mineral of Nitsch, White and Heller than that of Murashige and Skoog. But the reverse was observed in autotetraploid Nozaki-hakusaki. (2) Seed set in the capsules was observed in all the culture media without vitarnins. (3) Seed set in the capsules and percentage of germinated seeds were good from 17°C to 27°C in diploid Seppaku-taina and were best at 17°C in autotetraploid Nozaki-hakusai. (4) Seed set in the capsules and percentage of germinated seeds were good in comparatively wide range light intensity in both diploid Seppaku-taina and autotetraploid Nozaki-hakusai. (5) Seed set in the capsules and percentage of germinated seeds in excised ovaries were different between the sibmate of diploid Seppaku-taina and autotetraloid Nozaki-hakusai.