Abstract: By making use of the distinguishing features of repetitive imagery of the same area by satellite remotesensing.a method of extracting water areas at different tidal levels from the images of bays at different times was adopted to establish a calculating model for tidal surface and a method of finding a sum by layers was used to establish a calculating model for the deposition parameter.Moreover,by making use of the calculating models for the deposition parameter and for tidal level,the deposition parameter for the sea area less than 0 m was calculated for the Haikou Bay at two different periods of time:during the period of 1965-1984 the total amount of deposits was 4.8 ×10⁶m³,and the sedimentation rate was 2.5×l0⁵m³/a;during the period from 1984 to 1990,the total amount of deposits was -8.9×10⁵m³ and the sedimentation rate was -1.5×10⁵m³/a.