Synthesis of Ca-Fe-O using solution mixing method employing CaCO3 and Fe2O3•H2O has been conducted. Extraction of limestone as the raw material of precipitated calcium carbonate (PCC) and iron sands as that of Fe2O3•H2O was prepared to explore various compound of C-Fe-O, where the CaFe4O7 phase is mainly expected. The PCC and Fe2O3•H2O each are dissolved in 1 M HNO3 and mixed to be most homogeneous. The results of the synthesis are characterized by DTA/GTA and then sintered at temperatures of 800°C, 900°C and 1000°C.The sintered samples were characterized by XRD, FTIR, and VSM. The sintering temperature at 800°C, 900°C and 1000°C gave result the phase content of CaFe4O7 being respectively 55.42%, 44.55% and 36.39%. Other major phases in the Ca-Fe-O samples consist of Ca2Fe9O13 and Ca4Fe14O25. The remanence value of the corresponding samples is 2.11, 1.28, and 1.74 emu/g respectively.