Abstract: The paper is on the effect of soil moisture and soil density of two kinds of soil on soil cone index. The conclusions are as following. The cone index curve is hump-shaped with the variation of soil moisture. The maximum moisture at which the maximum soil cone index occur is nearly constant for a kind of soil, but for different soils the value is varied , with the increase of soil density, the relevant maximum cone index will increase, and the relation between them is one of power function:CI=0. 00939ρ^7.386,r=0. 999;The relation between cone index and soil moisture,soil density is one of power f unction :CI=a₁ρ^a2 ω^a3,and the statistical constant, will Vary for different kinds of soil.