Polyelectrolyte complex (PEC) is produced as a result of mixting polycations and polyanions. Since PEC has strong bio-compatibility, attention has been paid to its applications such as to prostheses for sites of tissue defect. In this study, PEC coating was applied to implants with the aim of reducing the period required for achievement of osseointegration of the implant and bone and increasing contact area. Thus post-implantation tissue reactions were investigated. As a result, the PEC-coated Titanium (Ti) and Hydroxyapatite (HA)-coated implant required shorter periods for achievement of osseointegration than the non-PEC-coated implant used as the control, the width of the bone trabeculae formed was increased, and the bone contact ratio was accelerated. These results suggested that PEC is a useful biological material for reducing the period required for achievement of osseointegration of the implant and bone and for increasing the contact area.