The distribution and breeding status of the Red-crowned Crane Grus japonensis were recorded from the air. Flights were made in a light plane over marshes, along rivers and lakes, in eastern Hokkaido from May 31 to June 2, 1986. Flying time totalled 15 hours and the distance covered was about 1, 810 km.Fifty seven incubating and brooding paris were found; 47.4% of them were in Kushiro, 45.6% in Nemuro and 7.0% in Tokachi. In the Bekanbeushi area of Kushiro breeding pairs were much fewer than usual, but the reason was not clear. Though hatching occurred earlier in Kushiro than in Nemuro in 1984 and 1985, the ratio of incubating and brooding pairs was similar in both districts this year, suggesting that simultaneous egg laying or hatching occurred there. 40.1% of the population were engaged in breeding activities and the mean number of chicks per brooding pair was 1.33. By the survey date half of the non-breeders including juveniles had already moved from the wintering grounds in Kushiro to Nemuro.From the air, 37% of the population in Kushiro were found in woods and on artifacts such as farm lands, roads, or banks, but less than 1% in Nemuro. Meanwhile 52.5% of the population in Nemuro were observed beside or in water, but only 19.6% in Kushiro. These observations indicate the difference between breeding habitats in the two districts. Excepting chicks, 275 individuals were observed, which were only 72% of the population counted at the feeding stations last winter. More precise surveys are necessary in the breeding season in order to locate the rest of the population.