The objective of the present study was to assess the health effect of houseplant. we selected 22 households of newly-built apartments and 17 asthma patients. Before intervention in the households, we conducted clinical survey investigations during April and October, 2006. In this study, 6 species of houseplants known to be eco-friendly and 14 other plants were recruited. While the clinical research items were lung function, erythrocyte sedimentation rate(ESR), white blood cell count(WBC), total eosinophil count(TEC) and total-immunoglobulin E(T-IgE). There was no association between the intervention and the estimated inflammation reaction and allergic reaction. However, peak expiratory flow rate(PEFR) of evening data were positive effect in the intervention asthma-patients households compared with the non- intervention. Keywords：Houseplants, Housekeepers, Asthma patients, Health effect