Despite of ferrite pearlite structure, microalloyed and controlled rolled bar revealed good fatigue property almost equivalent to quenched and tempered plain carbon steels whose microstructure was tempered martensite. Detailed study was carried out to give a comprehensive interpretation for this phenomenon. The relation between static strengthening mechanisms and fatigue property was investigated quantitatively, using low and medium carbon steels conventionally or controlled rolled with variation of Si and Mn contents and V or Nb additions. As a result of this, it was clarified that each strengthening mechanism showed different contribution in improving fatigue limit. Compared with grain refinement, pearlite and dislocation strengthening, both solid solution and precipitation strengthening improved fatigue limit efficiently as well as dispersion strengthening. This was caused by their effectiveness both in preventing dislocation from migration under cyclic loading and in strengthening ferrite matrix comparatively uniformly.