Calcium phosphate (CaP) particles aimed at specific applications including dental defect filling, bone tissue engineering and drug delivery may be engineered by different methods based on solution chemical precipitation. The understanding of CaP particle morphology evolution during precipitation is of great scientific interest not only from a fundamental point of view but also because morphology directly or indirectly determines the applicability of the particle. Citrate ion, widely known as a minor bone component, plays an important role as crystal habit modifier and crystal growth inhibitor. However the prediction of CaP growth morphologies in presence of citrate ion is still a challenging issue because the mechanism of citrate and CaP interactions is not yet clearly understood.