A method of testing the oxidation resistance of an alloy comprises applying a layer of salt on the surface of the alloy (54) and placing the alloy in a furnace (56), the furnace being at a predetermined temperature of at least 1000°C and containing an oxygen containing gas. The alloy is maintained in the furnace (58) at the predetermined temperature for a predetermined period of time and then the alloy is removed from the furnace (60) and the alloy is allowed to cool to ambient temperature or other suitable temperature. These steps (54 to 60) are repeated for a number of times to maintain the salt on the surface of the alloy at a level of 0.5 to 30µg cm- 2 h -1 . The alloy is weighed periodically (52, 64) to determine the oxidation resistance of the alloy. The advantage of the procedure is that the addition of salt reduces the time to test the oxidation resistance of the alloy and the addition of the salt mimics the degradation of the alloy in a real working environment in a gas turbine engine. The alloy may be a superalloy for a gas turbine engine component or a coating alloy for a gas turbine engine component.