Taken the development of a marginal oilfield in Beibu Gulf of the south China sea as an example, contrastive study on two foundation types of the production and storage platform is carried out from the perspectives of foundation bearing capacity, in-place motion response and steel consumption. The results show that: mat foundation is of higher requirement of soil surface smoothness; spud-can foundation is more adaptive to site; when the site has thin soft clay surface, skirt board must be added to mat foundation to prevent sliding; it is necessary to evaluate the possibility of puncture failure for spud-can foundation; in-place motion performance of mat foundation platform is better than that of spud-can foundation platform; the steel consumption of spud-can foundation platform is less than that of mat foundation platform. In the foundation selection design of mobile production and storage platform, oilfield parameters and environmental geological conditions should be considered comprehensively.