The one dimentional consolidation of a clay layer sandwitched between two pervious sand layers has been solved mathematically by K.Terzaghi. The tables and diagrams for degree of consolidation are easily found in textbooks on soil mechanics. But engineers and researchers often have to make interpolation to get a value of degree of consolidation for a certain time factor, because in the most of the tables or diagrams, the intervals of time factors for which the values of degree of consolidation are given, are relatively large. To eliminate such inconvenience, the values of the degree of consolidation were calculated for the small intervals of time factors with an electronic digital computer, TOSBAC-3400. The results are tabulated as shown in Table 2. A program for the calculation written in KT-FORTRAN which is similar to IBM 709/7090 FORTRAN II is listed in Table 4. The accuracy of the calculation was examined by a trial calculation with the program in Table 5. It was confirmed that the values of the degree of consolidation calculated herein are given correct at least to five decimal places.