Abstract: In this poper,the chlorine ions nuclei data,observed in Yonxing (xisha islands) during November,1987,are analyzed. The main results are:1) The average concentration of chlorine ions nuclei with dry diameters larger than 2μm is 878 per litre and the average salt content is 105. 4μg/m³,in which the special giant nuclei with dry diameters larger than 4μm have 190 per litre. The largest dry diameter of chlorine ions observed reaches 57μm,which are larger than that observed there during the South west summer monsoon. The spetrum type shows quasiudriodal and exponential lapse. 2) The Salt content decreases with the height over sea surface. 3) The concentrations of chlorine ions nuclei reach the maximum value at 08 o'clock,and minimum at 02o'clock.