The fluxoturbidite in delta front is an important reservoir sandbody distributing in deep water environment, and it is an important lithologic hydrocarbon reservoir in lacustrine basins. The delta depositional system generally has three topography slope breakpoints, namely the breakpoint between topset and foreset, the breakpoint between delta foreslope and prodelta and the breakpoint between delta depositional system and normal lacustrine depositional system, of them the topography grade of the foreslope is the biggest. The topography grade of the foreslope is one of the key factors which control the forming of fluxoturbidite. The slumping action occurs in the top of foreslope, and fluxoturbidite mainly distributes the bottom of the foreslope and the outside of the prodelta, these zones are topography slope breakpoints in the delta depositional system. The grade of the foreslope decides the location of the slope breakpoints in the outside of prodelta, the bigger the grade, the smaller the distance between the breakpoint and the foreslope. The quantitative correlation formula between the grade and the distance is established based on the fine dissection of Dongying Delta.