Abstract: In some parts of Qinghai,the saline soil having sodium sulfate content of less than 1% will also has salt-inflation,and dissolved subsidence does not occur in the ultra-chloro-saline soil.An intensive demonstration and research was carried out for the saline soil.Based on investigation data and facts,some new understanding and new perspectives were obtained.Building materials due to salt expansion has caused damage.The geological environment tends to play a decisive role.The relevant specificati...