The South China Sea monsoon is not only a main component of Asian monsoon system, but also plays an important role in the weather and climate over the surrounding areas and the globe. However, because of the insufficient observation data, it is self evident that the large-scale field experiment over SCS is very important to deepen understanding East Asian monsoon. In this paper, the composite experiment, modelling and data assimilation, especially the atmospheric observation, oceanic observation, air-sea interface observational network as well as satellite observation are introduced in detail.