Abstract: ObjectiveTo study the immunologic injury in mice of formaldehyde(FA)inhalation.MethodsThirty KM mice were randomly divided into 5 groups as following:negative control group,1,3,5 mg/m³ FA inhalation group and positive control group.Mice were exposed to different dose of FA by inspiration in a static total enclosure chamber for 14 days.The relative weight of spleen and thymus was calculated;The contents of CD₃,CD₄,CD₈ of spleen and thymus were measured with immunocytochemistry;The swallow function of macrophage in mice was measured with the CRBC swallow experiment;The delayed type hypersensitivity of mice,the quantity of antibody forming cell and lymphocyte function transformation were measured separately by the typical method.ResultsThe relative weight of spleen and thymus of mice were decreased(P<0.05 or P<0.01);the content of CD₃,CD₄,CD₈ of spleen and thymus of mice were decreased also,at the same time,CD₄/CD₈ was increased obviously(P<0.05 or P<0.01)when mice treated by FA vapor.Both lymphocyte function transformation of spleen,the intensity of the later allergic reaction and the quantity of antibody forming cell showed a significant decline tendency with dose increased in FA inhalation group compared with negative control group(P<0.05 or P<0.01);The swallow function of macrophage had obvious significance in FA inhalation groups compared with the negative control group(P<0.05).ConclusionThe overall immunologic injury were induced by formaldehyde inhalation in mice.