The aqueous-gel-tape-casting process is a novel technique fabricating flat ceramic materials. Employing the mechanism of three dimensions net structure formed by polymerized organic monomers, the high strength green bodies are formed by the net structure and ceramics particle filling in it. In the present work the influence of the organic monomer concentration and pH value and the polymerizing temperature and the concentration of initiator and catalyst on polymerization of the nanosized 3Y-TZP slurries during the aqueous-gel-tape-casting process was investigated. The results show that the polymerizing rate of the organic monomers increases greatly with the increase of the concentration of organic monomer in slurries. To ensure the proper polymerizing time, the concentration of the organic monomer solution must be controlled in the range of 10wt%~40wt%. The polymerizing rate of the organic monomers changes evidently with the different pH values. The higher the pH value, the lower the polymerization rate. The proper pH value is between 9~10. The polymerizing rate of the organic monomers increases with the increase of the temperature. Exceeding 35oC the polymerizing rate of the organic monomers changes greatly. The proper polymerizing temperature is from 35oC to 45 oC. The polymerizing rate of the organic monomers increases evidently with the increase of the concentration of the initiator and the catalyst. For perfect forming properties the concentration of initiator should be controlled in the range of 10wt% to 40wt%, the concentration of catalyst is about 0.20vol %.