The electrokinetic motion of mixture in an induced-charge electrokinetic micro-mixer is simulated numerically in this paper. An electrically conductive flap is mounted in the micro-mixer. A Y-shape micro-mixer is considered with two entrances. In first entrance, a sample species with a concentration of Co is considered and for other one, a sample species with concentration of zero is used. A 2D numerical model is utilized to determine the concentration, the electric, and the flow fields. All simulations are performed using the COMSOL Multiphysics 3.5a software. The effects of flap installation, flap position, and electric field intensity on the concentration distribution and mixing efficiency in the micro-mixer are investigated. The results showed that vortices were formed in electrolyte solution by mounting the electrically conductive flap in the micro-mixer due to the interaction of the applied electric field and the induced surface charge on the flap. These vortices improved the flow mixing significantly. Moreover, the species mixing in the micro-mixer is improved by decreasing the electric field intensity for 35.6 < E < 51.5 while, it is decreased by a decrease in the electric field intensity for 33.7 < E < 35.6. It is better to mount the flap in the regions near the throat of micro-mixer.