In this research, the fatigue crack growth(FCG) behavior of nickel based powder metallurgy superalloy used in aircraft turbine disk was investigated. FCG tests were conducted at room temperature, 600℃, 650℃ and 700℃ for various stress ratio. In order to measure fatigue crack length, the direct current potential drop(DCPD) method suggested by ASTM E647 was used for tests. As the results of tests, the fatigue crack growth rate increased with increasing stress ratio and temperature. So as to analyze fracture mechanism, fractography was performed by using scanning electron microscope(SEM).