Genomic DNA PCR (polymerase chain reaction) method must need to extraction step. We collected to the leukocyte that is only to have a nuclear and DNA in whole blood component. The exofcted leukocyte was applied to the PCR method in directly. A high effciency microfluidic chip was designed to extract leukocyte from whole blood using the lab-on a chip technology. This chip was able to the fast time and low chemical volume by 3-fold.