Famous Miner - Palmgren linear damage rule has been presented for 70 years. Because of the complicacy of fatigue research, no model could be compared with the Miner rule in engineering application to this day. Fatigue cumulative damage rule has been perfecting and developing. Based on the characteristics of fatigue damage and cumulative damage rule, this paper divided the rules of ascertainable fatigue cumulative damage rule into two main categories. One is linear cumulative damage rule. The other is non-linear cumulative damage rule (NLCDR). The latter can be classified into five categories： NLCDR based on damage curve method; NLCDR based on the degradation of materials performances; NLCDR based on continuous damage mechanics; NLCDR considering the effects of load sequencing on the fatigue life; NLCDR based on energy rule. The representative model of every category is analyzed in physical background and briefly commented. The main questions of fatigue cumulative damage rule are answered. Finally, the several issues are discussed.