Nano indentation low cycle fatigue test has been performed in AZ61 Mg alloy to study the effect of cyclic loading. The cyclic load-depth curves are observed in aged and solution treated conditions. An indentation fatigue depth propagation law is used to analyze the cyclic behavior of the alloy. The increase in steady state depth propagation rate with increasing stress intensity has been reported which is qualitatively similar to the steady state growth rate of a fatigue crack. It has been found that the depth and depth propagation rate have different values in solution treated and aged condition under the same loading parameters. The results are analyzed by considering the role of slip and twinning in the deformation of solution treated and aged conditions. © 2016 Elsevier B.V.