Objective:To explore the microstructure of the bonding interface between the fiber post and root canal wall,which was processed with different bonding material and methods. Methods:Fifteen sound canines were root filled after sectioned transversely 2mm coronal to the labial cemento-enamel junction. Fiber post was placed with three different root canal adhesive material(n = 5):RelyX Unicem(3M),DC core(Kuraray),Luxacore Z. Each root specimen was cross sectioned across into three samples (+/- 2.0 mm in thickness). In each group 3 samples were chosen to observe under Scanning Electron Microscopy(SEM). Results:SEM observation of the ashesive interface specimens showed that different bonding treatment caused to form varying degrees of hybrid layer and resin tags. Conclusion:SEM observation of the ashesive interface specimens reveals that the mixed layer and resin tags are the key factors in approaching better bond.