Questionnaire　survey　and　field　measurements　of　indoor　environment　of　apartments　in　a　Shanghai　local　area　(referred　as　＇houses＇　hereafter)　and　the　health　status　of　resident　4th　and　5th　grade　students　therein　(referred　as　＇the　children＇　hereafter)　were　conducted.　Survey　results　suggested　that　58.6%　of　the　children　had　at　least　one　respiratory　disease　or　allergy　symptom.　A　subsequent　case-control　study　confirmed　that　the　cumulative　frequency　of　relative　humidity　exceeding　70%　in　the　case　group　was　obviously　higher　than　that　of　in　the　control　group　in　winter　season,　whereas　fungi　in　indoor　air　in　the　houses　of　the　case　group　were　higher　than　that　of　the　control　group.　In　consequence,　it　is　suggested　that　the　indoor　environmental　factors,　particularly　those　related　to　dampness,　may　give　rise　to　these　symptoms.