Abstract: High and low cycle fatigue performance of micro-alloyed and TMT rebars are compared through experimental investigation. Micro-alloyed rebar shows better fatigue performance than TMT rebar. It is experimentally observed in both micro-alloyed and TMT rebars that for high and low cycle fatigue,crack initiates form the transverse rib root and propagate along the same region. From finite element simulation,it is noticed that the stress concentration takes place at the root of the transverse rib and stress triaxiality becomes higher in the same region. At the transverse rib root,tensile strain accumulation is noticed in simulation. The experimental observation is explained with the help of simulation result that fatigue crack initiate and propagate along the transverse rib root.