This study was conducted to evaluate the quality of indoor air and health-related parameters (allergic rhinoconjunctivitis) of subject of study (control group and sensitive group) in two schools. The schools were categorized into two groups of newly-built school and the school older than 5 years. Removal of indoor pollutant was investigated according to volume rates (0%, 1.5%, 3%) of indoor plants inside 3 classrooms respectively. The chemicals of indoor environmental research were PM10, Volatile organic compounds (toluene and benzene), formaldehyde, temperature and humidity. ARIA (Allergic rhinitis impacts on Asthma) test was used to assess health effect for 151 students. Also, The variation of SBS symptoms for students in classroom was measured by intervention. With increasing volume ratio of classrooms, there were positive and significant results between the indoor pollutant and student\'s health score. Students showed improvement health score during the period of putting indoor plants, which was facilitated by the placement of indoor plants at newly-built school classroom of indoor plants volume ratio 3%. From the results above, it could be tentatively effective newly-built school classroom of indoor plants volume ratio 3% improve indoor air quality and student\'s health score. Keywords : Indoor plants, Indoor air quality, Elementary school, Health score