Based on the data of 123 sea samples from Jimo city,Qingdao and the historical investigation data,this paper made a statistical analysis of the relationship between the indoor particle size parameters and the in-situ geotechnical characteristics,and obtained the sedimentary environment division of the study area and the correla-tion between the particle size parameters and the geotechnical parameters.The study showed that the sedimentary environment of the study area could be divided into coastal sedimentary environment,transitional sedimentary en-vironment,shallow marine sedimentary environment and residual sedimentary environment.The correlation be-tween grain size parameters and geotechnical parameters in different sedimentary environments was good,but the correlation formula was obviously different.These relationships could provide a basis for understanding the engi-neering geological conditions of the study area,and provide a reference for inversion of the engineering geological characteristics of the regional seabed by using the existing research data.