The main goal of this study is to report experimental evidence about the accumulative fatigue damage behavior of CK35 steel alloy at room temperature and zero main stress (R = -1) . A non-linear accumulative damage model based on static and dynamic deflection is proposed, considering the loading sequence into account and the constant S-Ncurve. Satisfactory predictions of cumulative fatigue life have been observed when applying the proposed model to the two block loading sequence. Comparison between LDR and proposed model has been made. It was found that LDR can underestimate the fatigue damage and the proposed model showed good agreement with the experimental results. A non-linear damage model seems to be a proper choice for predicting the cumulative fatigue two block loading histories.