pH effect in synthesize of tricalcium phosphate from eggshell via precipitation method has been performed. This study aimed to determine effect of pH tricalcium phosphate compounds which modified to 7, 8 and 9. Calcined eggshells were used as calcium source and phosphoric acid acts was source of phosphate. Ammonia acted as pH modifier in tricalcium phosphate synthesis. Various characterizations have been used to characterize producct. XRF showed there were 96.95% CaO content in calcined eggshells. In FTIR, tricalcium phosphate was characterized by the phosphate absorption band group (PO43-) bending marked which was absorption bands at 1074 cm-1, 1070 cm-1 and 1145 cm-1 for pH 7, 8 and 9. XRD peaks showed that tricalcium phosphate formed crystal structure and nanosize particles. Agglomeration had shown by SEM image formed because of precipitation process