Abstract: Fluorine in phosphogypsum can restrict the application of phosphogypsum in fields of cement,architecture and so on,so it′s very important to know the fluorine content in phosphogypsum.Determination methods of total fluorine content in phosphogypsum were discussed.Through experiments,it is put forward that use sodium carbonate to melt phosphogypsum sample;use sodium citrate-glacial acetic acid as total ionic strength adjustment buffer(TISAB) and adopt ion selection electrode method to determine total fluorine content in phosphogypsum.The max limit of determination (MLD) for mass concentration of fluorine ion by this method was 0.34 mg/L,recovery rate of florine ions was 88.5%~90.3%,liner range of mass concentration of fluorine ion was 0~5 mg/L，liner correlation coefficient was R<SUP>2</SUP>=0.999 1,and relative standard deviation was 1.2% (n=7).This method is a simple,fast,and high-sensitive method for determining total fluorine content in phosphogypsum.&nbsp;&nbsp; <BR>