Micro Total Analysis Systems (micro TAS) are micro scale devices which can be used for many kinds of fluid processes. Micro TAS has many advantages for its scale and has been attracting a lot of attention. The application areas range from engineering to medical. Micro droplet generation is one of the basic techniques of micro TAS. Numerical simulation is useful for optimization of droplet generation process. The objective of our study is to develop a three dimensional code which can simulate micro droplet generation and validate our code with comparison between simulation and experimental results.