Micro droplets produced from the introduction of immiscible fluids of organic phase and water phase are useful for a wide range of applications, especially in the field of chemistry and biochemistry. Smaller micro droplets in the microfluidic system increase the efficiencies of chemical reaction and extraction in liquid-liquid interfaces. In order to realize high generation rate of the uniform oil-in-water droplets, we invented the multi-stage divergence system. The droplet generation rate was achieved by the uniform micro fluidic separation up to 16 micro droplets from one droplet. The maximum generation rate was 1760 droplets/s and the deviationof their diameters was smaller than 3%. The generation rate and diameter were well controlled by the flow rates of water phase and organic phase. We also developed the fabrication of nano-porous polymer microcapsules using self-assembly of the block copolymers in the multipahse microfluidic system. The spherical microcapsule was successfully fabricated with the polymer thickness of 0.5∼1.5 μm and nano pores.