Abstract: Effects of different mineral elements (Ca, Mg, Zn, Mn, Fe, Cu) on the hardness of dry bean curd were studied by adding them in dry bean curd processing. The result showed that adding of Ca 2 + 、Mg 2 + 、Zn 2 + and Fe 3 + had significant influence on the hardness of dry bean curd, and with the increasing of the ions, the hardness increased differently. While adding of Cu 2+ and Mn 2+ did not have significant effect on the hardness of dry bean curd. The reason of this might be the different ionic radius and electronegativity of different ion that caused the different forms of combination with soybean protein, thus affect the hardness of dry bean curd.