Pugionium cornutum is a special species in China and Pugionium dolabratum was listed an endangered species in 1992.Took sand from the natural habitat of P.dolabratum and used for indoor artificial simulation test,we investigated the adaptation of seed germination,seedling emergence and seedling growth in P.cornutum and P.dolabratum to sand moisture content.Results showed the optimal sand moisture content for seed germination was from 6% to 12% for both P.cornutum and P.dolabratum.The optimal sand moisture content for seedling emergence was from 6% to 16%.When sand moisture content was under 2%,seeds could not germinate;when sand moisture content was under 3%,seedling could not emerge and settle.The optimal sand moisture content was from 6% to 12% for P.cornutum and P.dolabratum’s seedling development.From 3% to 8% for P.cornutum and from 4% to 8%,for P.dolabratum have their significantly highest root-top ratio.The seed germination mechanism of P.cornutum and P.dolabratum has strong adaptability to sand environment.In order to adapt to low sand moisture content,seedling allocated more biomass to root to absorb deeper level of water.