A novel passive micromixer with rapid mixing and low pressure drop has been successfully demonstrated by simulations and micro-fabrication. The structure of this micro-mixer contains one main channel, two sub-channels for injecting the other specie and some baffles in the main channel to form mixing chambers. Adding baffles to the main channel will produce the recirculation to increase the contact area of the fluids and form nozzles. So, this type of design can improve mixing efficiency. The better stream mixing is attributed to the higher baffle, the more baffle number and the higher flow rates. From the design aided by simulations, the design with 3 baffles of 300 μm height is adaptive for uniform mixing (90% mixing) and low supplied pressure of 4750 Pa at Re of 100 in the 3D simulation.