Low cycle fatigue crack growth behavior of 2 1/4 Cr-1 Mo Steel is investigated under fully reversed strain control at room temperature for center cracked specimen. Application of the cyclic J -integral (Δ J ) approach is attempted. Experimental results for center cracked specimen under fully reversed strain control are also compared with those for center cracked specimen and CT specimen under slop line control, and those for CT specimen under load control. It is known that Δ J is a successful parameter for low cycle fatigue crack growth and the estimation of crack opening behavior rather than crack closure behavior is important for the improvement of accuracy under fully reversed strain control. It is important to verify the crack growth estimation by the experimental data in application of Δ J to structural components, therefore some investigation is made for the prediction of low cycle fatigue crack growth in center cracked specimen.