Synthetic biology is a new branch of interdisciplinary science that has been developed in recent years for the application of biological technology. The main purpose of synthetic biology is to develop basic biological functional modules, and through rational design, develop man-made biological systems that have predicted useful functions. In this talk, I will report a few synthetic biology researches that conducted mainly by the undergraduate students at Peking University, under the project of International Genetically Engineered Machine Competition (iGEM): Synthesis of push-on-push-off biological switch；General machine for in vivo protein evolution; and synthesis of "Bavlov bacteria", and the application of biological network reverse engineering to get semi-log dose response function. The first research got the Grand price, the best Information project price and a gold medal in iGEM 2007, the third research got gold medal in iGEM2009, and the last research got the first running up price, the best environment project price and a gold medal in iGEM 2010. These practices indicate that undergraduate student can be actively involved in the synthetic biology research