Applying statistical method to the CSK data, a relation between density (σt) and temperature (T) of sea water of the Kuroshio in the region to the east of Taiwan has been found. The data of eight hydrographic section across the Kuroshio in the region to the west of 130°E were chosen and calculated for examining this relation. The value of root-mean-square error of the density obtained by this relation.The value of root-mean-square error of the density obtained by this relation is 0.06×10-3g?cm-3. Through the comparision of the results of the dynamic calculation by this T-σt relation with those by classical T-S-σt relation, it was shown that the error of the current velocity by this relation is permissible. Therefore, it is possible to calculate the geostrophic current velocity simply from temperature, if, only the rough current structure of the Kuroshio in the region is required.