Abstract: In order to study the ratcheting behavior of Ti-6242S at an elevated temperature, the uniaxial tensile, strain and stress controlled cyclic experiments on the alloy were performed in the range of 25~520℃. Experimental results show that the elastic modulus and nominal yield stress of the alloy decrease, but the elongation increases with the temperature increasing; the alloy is characteristic of cyclic softening in the temperature range. Under the stress-controlled cyclic loading conditions, the alloy exhibits obvious ratcheting behavior; the ratcheting strain increases with the stress amplitude and temperature increasing, and related to its loading history, the ratcheting strain consists of the plastic strain and creep strain, simultaneously. Large stress amplitude with a constant mean stress will result in the coupling effect between ratcheting behavior and damage, which sharply reduces the fatigue life of the alloy.