This paper describes the development of microcapsules for shock wave drug delivery systems (DDS). Especially capsule structure and driving force is investigated. In the first step, the neutrophil based capsule is made for DDS instead of polymer membrane capsule. When some part in our body inflames, materials, whose name is cytokine, are released. These materials pull neutrophil, one of white blood cell, toward inflamed part. It is said that neutrophils are moved to inflamed part by gradient of cytokine concentration that is called chemotoxis. This mechanism is immune mechanism. If we can control chemotasis of neutrophil, it follows the development of application in the fields of immunity and drug delivery system. In the second step, the motion of neutrophil by gradient of cytokine is investigated and it was found that the driving force of neutrophile is caused by the gap of diffusion coefficient at the interface.