This paper describes the measured results on carbon dioxide concentrations in 27 temporary houses in summer and winter in Sendai city after half a year of the Great East Japan Earthquake. The carbon dioxide concentrations in temporary houses were high generally. In summer, the median value in 7 temporary houses (26%) and 75% tile value in 20 temporary houses (74%) exceeded 1,000 ppm. Moreover, concentrations in 17 residences (63%) exceeded 5,000 ppm, and highest was about 11,000 ppm. In winter, the median value and 75% tile value were both higher than that in summer respectively. Although ventilation is effective to reduce the indoor carbon dioxide concentrations, temporary house where air volume is small, when an open type combustor was used in winter, indoor carbon dioxide concentration might exceed 10,000 ppm.
