Low firing temperature substrate were synthesized through tape casting and sintering of glass with cordierite composition and then their properties were investigated. Even though the dielectric properties and XRD patterns of substrates, obtained by tape casting and sintering at 900~100$0^{circ}C$ for various periods, were similar to those of substrates obtained by dry pressing, the sinterability was enhanced. The substrates were thin and the size was 0.6$ imes$50$ imes$50mm. From the results of dielectric properties, the sinterability and X-ray diffraction pattern, the proper condition for cofiring process with conductor, Cu, was 90$0^{circ}C$ for 1h. The properties of the substrate are as follows; the dielectric constant was 5.31(at 1MHz), the dissipation factor was 0.0028, the apparent porosity was 0.28% and the main crystalline phase was $alpha$-cordierite.