Abstract: Anti-floating underground water table is a key parameter for the buildings whose foundations are buried below the underground water table. Based on the weather condition in Beijing and the engineering geological and hydrogeological conditions near the construction site, according to the underground water table data obtained from many year's monitoring, the main factors causing the change of the underground water table are analyzed and the highest underground water table of the construction site in the future is predicted. As a result, the anti-floating underground water table for the buildings in Yihai Garden in Beijing is determined.