This paper is aimed to investigate behaviour of vortex in 2-D step cavity with high Reynolds numbers$(3.2{ imes}10^{3},;10^{4},;3{ imes}10^{4},;5{ imes}10^{4};and;7{ imes}10^{4})$. The SOLA algorithm which is MAC type was adopted to solution method computing the flow field on irregular grid. In case of $Re=7{ imes}10^{4}$ flow behavior is steady bu periodic unsteady sinusoidal fluctuation of local velocity and kinetic energy is found for $Re=10^{4}$ Continuous movements of small eddies in the secondary flow regions are discov-ered for $3{ imes}10^{4}$ Generation of eddies and their active migrating behavior are detected over $Re=5{ imes}10^{4}$ resulting in complete unsteady and non-linear flow characteristics Furthermore a typhoon-like vortex(TLV) appears intermittently and rotates along the separation regions and boundary layers.