Observational study is carried out to clarify the behavior of vortices formed in the free shear layer of pulsating jet, and to compare that of a steady jet. The flow is visualized by hydrogen bubble method, and pulsating flow is generated using Scotch yoke mechanism. Obtained results are as follows: The frequency of vortex formation in the shear layer agrees with that of pulsating velocity at the nozzle exit regardless of the amplitude ratio of pulsating velocity. The contraction width of jets decreased as the amplitude ratio increased. The formation and growth of vortices in the case of pulsating jets are occurred at the upstream position than those in the case of a steady jet.