Indonesia is a country that has many types of freshwater fish, one of which is tilapia. The consumption of tilapia among the people of Indonesia is quite high. So that, it will produce a lot of fish scale waste. Fish scales can be used as a natural source of hydroxyapatite because they contain calcium. The aim of this study was to evaluate the effect of hydroxyapatite synthesized from tilapia fish scale (Oreochromis niloticus) on the shear bond strength of glass ionomer cement and resin modified glass ionomer cement to enamel layer. Hydroxyapatite was synthesized from tilapia fish scale (Oreochromis niloticus) by calcination method at 800°C. Sample was made from glass ionomer cement (GIC) and resin modified glass ionomer cement (RMGIC) combined with 2, 5 and 8%wt of hydroxyapatite, respectively. Sample was bonded to enamel layer of human premolar tooth. The shear bond strength of sample was tested by using Universal Testing Machine. The result showed that shear bond strength were increased for higher concentration of hydroxyapatite that added to glass ionomer cement or resin modified glass ionomer cement. The maximum of shear bond strength of GIC Group is 6,38 ± 0,05MPa after 8%wt hydroxyapatite addition. The maximum of shear bond strength of RMGIC Group is 6,59 ± 0,06 MPa after 8%wt hydroxyapatite addition. There were significance differences among all group tested (p <0.05). It can be concluded that hydroxyapatite synthesized from tylapia fish scale can increase the shear bond strength of glass ionomer cement and resin modified glass ionomer cement.