The present investigation has been carried out on a water-quenched 18-8 stainless steel in order to find the correlations of torsion or bending creep strength to tensile creep strength. And the analytical consideration due to von Mises criterion was added on the experimental results obtained. Tension creep tests were conducted on 8mmφ cylindrical specimen, torsion creep test on 8mmφ hollow and solid cylindrical specimens, and pure bending creep test on 6mmt×10mm plate specimen. All the test of the creep were made for 400 hours at 600° and 650°C. The machines employed in the torsion and bending creep test were made in our laboratory. The results obtained can be summarized as follows:1) The ratio of the torsion creep strength of hollow cylindrical specimen to tension creep strength for a mean creep rate of 2×10-4∼5×10-3%/hr during 300 to 400 hours were 45∼46% for 600°C, and 38∼42% for 650°C. On the other hand, the ratio derieved from the calculation based on von Mises criterion was 52% for 600°C, and 53% for 650°C.2) The ratio of the torsion creep strength of solid cylindrical specimen to the tension creep strength was 54∼56% for 600°C. This magnitude of ratio was smaller than the ratio of 64% obtained by calculation.3) The ratio of the bending creep strength to the tension creep strength was 141∼158% for 600°C, and 145∼160% for 650°C. On the other hand, the ratio obtained by calculation was 134% for 600°C, and 139% for 650°C.