Direct coagulation casting of alumina suspension via controlled release of high valence counter ions (DCC-HVCI) using calcium citrate as coagulating agent was reported. Hydrolysis of glycerol diacetate shifts the pH of suspension to weakly acidic region which helps to decompose calcium citrate and release calcium ions. The effect of concentration of glycerol diacetate and calcium citrate on the pH and viscosity of alumina suspension was investigated at 25 degrees C and 60 degrees C, respectively. The pH of suspensions with glycerol diacetate and calcium citrate decreases to 8.6 and 7.5 treated at 25 degrees C and 60 degrees C, respectively. It is indicated that high viscosity is achieved by adding 2vol% glycerol diacetate and 0.5wt% calcium citrate which is enough to coagulate the suspension. Green body with compressive strength of 1.0MPa is obtained by treating the alumina suspension with 2vol% glycerol diacetate and 0.5wt% calcium citrate at 60 degrees C for 1h. The alumina ceramics sintered at 1550 degrees C have homogeneous microstructure with relative density above 99.0%.