The mechanical behavior of the Ti-6A1 4V alloy denture base made by superplastic forming was studied using various bending tests. The bending strength of the Ti-6A1-4V alloy plate made by superplastic forming was as strong as that of the casting Co-Cr alloy plate with the same thickness. The bending strength of the superplastic forming plate with channels was higher than that of the plain plate. Increase in the arch curvature of the plate decreased the strength, because increase in the arch curvature of the plate decreased the thickness of the superplastic forming plate. Similar results were obtained for the clinical models. The appropriate original thickness for superplastic forming denture base was derived empirically from the experimental values for depth of palate.