Abstract: Floatage force often occurs and produce strong effect on building in coastal area or other high ground-water level area. Therefore, foundation anti-floatage design becomes a key problem of construction in these areas. In general, anti-lift pile foundation is taken to counteract the adverse effect of ground water floatage to building in sub-ground engineering. But, anti-lift pile foundation is not the only measure and it has been proved times and again, so more economical and reasonable foundation is called in relation to certain engineering condition in design works. Based on certain engineering case, security and economical rationality of its foundation design is analyzed, and an optimized foundation scheme is put forward. The foundation design optimization could produced some inspiration to other foundation design.