In order to understand and improve properties of calcium phosphate bone cements, it is necessary to research processes during the cement setting. In the current research processes during setting of α-tricalcium phosphate bone cements with varied initial liquid phase pH values were investigated. Differences in initial liquid phase pH affected cement setting, but only insignificant influence on such cement properties as composition, compressive strength and pH was observed after cement specimens’ aging in water for 24h. It was determined that conversion of α-tricalcium phosphate to calcium deficient hydroxyapatite is faster if initial pH of cement liquid phase is acidic or neutral (pH 6 – 7).