Recent studies have revealed that the cohesion of calcium phosphate cement (CPC) might be a key property to ensure a safe and reliable clinical use of CPCs. Our study focused on the evolution of cohesion time and remaining percentage of TTCP/DCPA phosphate cement with changing factors in order to uncover the dependence of the cohesion of CPC on setting solutions and incubation liquids. Several factors were considered, including incubation liquids, concentration of setting solutions, powder to liquid (P/L) ratio, and polymer additive in setting solution. Results showed that the total ion osmotic pressure of both setting solutions and incubation solutions had significant influence on cohesion. Using physiological saline and simulation body fluid as incubation liquids indicated that the species of ions sometimes had much more profound effect on cohesion. Results of varying P/L ratios showed a great dependence on setting liquids, and a spot of water-soluble polymer additive was proved to be positive for cohesion.