The effect of pH value at different initial Ca/P molar ratio on the composition and crystal phase of the calcium phosphates synthesized through chemical precipitation method was studied in detail. After calcining at 900°C, the products were characterized by XRD and chemical analysis. The results showed that the composition and crystal phase of the resultant powders can be controlled by pH value at different initial Ca/P molar ratio. When Ca/P molar ratio was 1.667, pure HA was obtained at pH values of both 12.0 and 11.0. When initial Ca/P molar ratio was 1.500, pure β-TCP was obtained at pH value from 11.0 to 9.0. CPP was obtained at pH value from 6.0 to 4.0 when initial Ca/P molar ratio was 1.000.