Gel-casting has been widely studied for the last decade [1–5]. In this process, a slurry made from ceramic powder and a water-based monomer solution is poured into a mold, polymerized in situ. The gelled part is removed from the mold while still wet, and then is dried and fired. The dried green body is strong enough to be machined. However, the process is not perfect in that the polymerization of monomers is difficult to control in the ceramic suspension. Reductive agents usually restrain the free-radical polymerization of commonly used acrylamide. In addition, acrylamide is highly toxic. Therefore, new gelcasting process with a reduced toxicity have been investigated [6–8]. In fact, many polymer solutions can gelate under suitable conditions [9, 10], such as agarose, gelatin and sodium algaecide. Some of them have been employed in food industry [10]. When the polymer is dissolved in solvents, the molecular chains attract each other to form a three-dimensional network by hydrogen bonds or Van der Walls forces. The gelling property of agar has been used in the water-based injection molding [11]. Recently, we have reported that ceramic suspension was gelled to green body using gelatin and agarose [7, 12]. However, the suspension containing agarose has to be heated up to 80 ◦C before casting, which easily results in water vaporization. In addition, both agarose and gelatin are expensive when they are employed in industry. Alginate is a type of gelling polysaccharide, which can be dissolved in water at room temperature and then gelled after casting by cross-linking with divalent metal ions at increased temperature. Like all cationexchangers the selectivity and strength of binding depend on both the nature of the cation and the properties of the polymer. Divalent and polyvalent cations and bound strongly by all types of alginate and effectively cross-link the polysaccharide to form a gel matrix. However, regions of polysaccharide form particularly strong chelation complexes with divalent cations, especially the calcium ion [13]. The mechanism of crosslinking in alginate gels can be considered in terms of an “egg-box” model involving cooperative binding of calcium ions between aligned polyguluronate ribbons as shown in Fig. 1 [10, 14]. The buckled chains of polysaccharide form a structure akin to the cross-section of an egg-box in which the calcium ions are the “eggs”. The binding of the calcium ion is strong because, in addition to the ionic binding to the carboxyl groups, various ring and hydroxyl oxygen atoms are able to chelate the cations. Although there are many salts containing calcium ion, such as CaCl2 · 4H2O, CaC2O4, Ca(C6H11O7)2, Ca(IO3)2 · 6H2O, which can react with alginate and crosses link together. However, it is generally very difficult to control the reaction rate for most of them. This makes it impossible to complete casting processing at certain period. Therefore, the divalent salts with a controlled reaction rate with alginate have to be considered. In other words, divalent cation concentration released from the salt can be adjusted with temperature or time. Examining the solubility of above salt substances at different temperatures, we found that Ca(IO3)2 · 6H2O is good for gelcasting processing because they have a lower solubility (0.17 wt%) at room temperature and a high solubility (1.38 wt%) at increased temperature of 60 ◦C. So Ca(IO3)2 · 6H2O was chosen in this study. In the present paper, the gelling properties of sodium alginate solution and resulting suspension with ceramic powder were investigated. The rheological behavior was examined. Near-net-shaped green bodies with different shapes were produced by the novel forming processing. Sodium alginate used is a commercially available fine powder with white color. Sodium alginate solutions with different concentration were prepared by stirring in deionized water at room temperature. The apparent viscosity of the solution was examined by a rotary viscometer (Model NXS-11, Chendu Instrument Plant, China). Fig. 2 shows the results of rheological properties influenced by the alginate concentration. For lower concentrations of sodium alginate of 0.5 and 1.0 wt%, the flow properties are almost Newtonian mold, and shear-thinning characteristics of alginates are obvious at high concentrations. These results are in good agreement with other reports [10]. It should be noted that the viscosity of the solution with 3 wt% alginate had a maximum value at the shear rate of about 35 s−1. This can be explained from the competition between promptly chain association and breaking down by shear. To examine the controlled gelling process of calcium and alginate, 1 wt% calcium iodate was dispersed in the 3 wt% alginate solution by stirring, and then moved the bake containing alginate suspension to water bath at 60 ◦C. Fig. 3 illustrates that the viscosity varies with time for the system. As a comparison, viscosity curves without calcium iodate was included in same figure. At the initial period, viscosity increases very slowly from a