Ultra-fine grained (UFG) pure titanium was prepared by equal channel angular pressing (ECAP) and rotary swaging (RS). Low cycle fatigue tests with strain ratios of - 1, - 0.5 and 0.5 for titanium were carried out at room temperature. Microstructure was observed by TEM after the fatigue test. The effects of strain ratio on cyclic hardening and softening properties, cyclic stress-strain relationship and fatigue life of materials were studied. The results show that the cyclic hardening of UFG pure titanium is more obvious with the increase of strain ratio; Low cycle fatigue life of ultra-fine grained pure titanium decreases with increasing strain ratio; Microstructure observation shows that under high strain ratio, the subgrain size is small and the number of subgrains is large, which hinders the movement of dislocations and leads to cyclic hardening.