Wharf slopes are often formed by the natural soil sedimentation.Soil parameters are space-variable,and the soil localized point variability can be changed to spatial variability based on the random field theory.The soil character random field is a stationary random field,and correlation distance is an important parameter which can reflect characteristics of the field.Based on the random field theory,CPT data has been used,then according to the relevant function method,the correlation distance of wharves soil is fitted and solved,and the work lays a foundation for the reliability study on the wharf slopes.