A series of ceramic glazes based on the SiO2-CaO-B2O3-Al2O3 system as sealant for intermediate temperature solid oxide fuel cell (ITSOFC) were investigated. Different ratios of B2O3/SiO2 and Al2O3/CaO were investigated to control softening process, phase separation, and crystallization. When B2O3/SiO2 ratio was in the range of 0.14-0.27, the glazes showed good wetting and bonding behavior with both 8 mol% yttria-stabilized zirconia (8YSZ) electrolyte and stainless steel interconnect which could satisfy the sealing demand at 850 degreesC. And the dimension stability can be kept for over 100h by introducing ceramic felt and controlling the glazes viscosity in the range of 10(4) to 10(6) Pas. By means of controlling Al2O3/CaO ratio in the range of 0.4-0.68, phase separation and crystallization were restrained effectively. After holding at 850degreesC for 100 h, non-crystalline network in the glazes could be found, and a suitable viscous flow could well relax thermal stress. The sealing was effective even after 10 thermal cycles. Element analysis showed a good chemical stability at the ceramic glazes/stainless steel interconnect and ceramic glazes/8YSZ electrolyte interfaces. (C) 2003 Elsevier B.V. All rights reserved.