The mass balances of calcium salts during the manufacturing processes of Tofu were established by conductometric method and chemical analysis method. During the manufacturing processes of soy milk and Tofu, 66% of solid and 63% of calcium was transfered from soy-bean to the soy milk, and 47.8% of total solid from soybean was transfered to the Tofu, respectively. When the $CaCl_2$ was used as coagulant, calcium contents in Tofu $(Y_{Tofu},;mg{cdot}Ca/g{cdot}Tofu,;wet;basis)$ and drained solution $(Y_{drained;soln},;mg{cdot}Ca/ml{cdot}drained;soln.)$ were linearly increased with the amounts of $CaCl_2(C,g{cdot}CaCl_2/ml{cdot}soy;milk)$ added in soy milk, and correlative equations between them were obtained as $Y_{Tofu}=0.3369;C+1.2689$ for Tofu$(moisture;content:;81.5{pm}0.5%)$ with r=0.9898, and $Y_{drained;soln}= 0.2899C+0.0399$ for drained solution with r= 0.9991. It was proved that conductometric method was reasonably applicable to the measurement of calcium contents of the products from every processes of Tofu manufacture except soy-bean. However the conductometric method was not recomendable in the case of $CaSO_4$ as coagulant due to its low solubility ana uneven distribution in soy milk and Tofu tissue.