The purpose of this study is to investigate the remineralization of enamel in the human tooth by fissure sealant containing various amount of hydroxyapatite. Prior to remineralization experiments, the necessary requirements of the dental fissure sealant, the curing depth and the curing time, were measured with the content of the hydroxyapatite according to the standard of ISO 6874. Various amount of hydroxyapatite was mixed uniformly using sonicator up to 20 wt% to the fissure sealant. In spite both the curing time and the curing depth were decreased with increasing the content of hydroxyapatite, all samples were satisfied the ISO requirements. Remineralization experimental samples were produced by bonding fissure sealant containing various amount of hydroxyapatite to human tooth enamel using manufacturer’s information. After exposure to the simulated body fluid at 36.5oC for 4 weeks, the bonding strength and the surface morphology were examined using Instron and scanning electronic microscope, respectively. The bonding strength between the fissure sealant and the human teeth was drastically enhanced with the amount of hydroxyapatite. The remineralization zone could be observed along with the boundary of hydroxyapatite and fissure sealant using a scanning electronic microscope.