The clinical retention of a multiple application of a pit and fissure sealant was evaluated at every 3 months after sealant treatments on the early carious first permanent molars in grade one or two elementary school children during school based fluoride mouthrinsing (daily; 0.05% NaF). Maxillary and mandibular teeth, CO and C1 teeth at sealant treatment, occlusal mesial and occlusal distal sites for maxillary teeth, and occlusal and buccal sites for mandibular teeth were differentiated and evaluated. Maxillary palatal sites were not evaluated because no early caries was detected in these sites.The ratio of teeth retaining sealant was 78.7% at the final examination. Sealant materials had not come away in 53.4% of sealed teeth during this survey period. The rate of teeth retaining sealant was significantly reduced after 15 months compared to at 3 months. The retention ratio of CO teeth and the site retention ratio of maxillary occlusal distal site were not significantly reduce dat any period compared to at 3 months.