The flow and mixing of fluid induced into the cylinder through each of the two intake ports of the spark ignition engine has been studied during intake and compression strokes on horizontal and vertical sections of the engine cylinder by experiment and numerical analysis. In the experiment in order to observe the flow and mixing process of fluid from each port, particles were alternately mixed with air flowing through each of the two intake pipes. And velocity vectors on the sections were measured by means of particle tracking velocimetry. The finite volume method was used in numerical analysis. Flow behavior and mixing of the fluid induced through each intake port were demonstrated in various crank angles and on various sections of cylinder during intake and compression strokes. Comparison between the experimental and numerical results were also made.