Abstract: Due to the change of environmental conditions and so on，basements without considering uplift are often floated and cracked during the construction process or to be used before completion of the project. Therefore，how to analyse and deal with the float of the basement is worthy of being studied and discussed by engineers. Based on a gym，whose beams，columns and slabs of foundation were cracked and floated，the analysis was implemented and the related treatment scheme was proposed to meet the requirements of serviceability. The experience can be used as reference for analyzing and treating similar accidents.