In this paper, the characteristics of runoff and sediment yield of two-dimensional plane and three-dimensional cone-shaped slopes under different gravel contents were studied through the indoor simulated rainfall test.The results showed that: (1) The slope velocity and runoff rate per unit area showed a trend of "rapid increase, slow increase and stable fluctuation" with the runoff time. (2) The average flow velocity and average runoff rate per unit area decreased with the increase of gravel contents.When the gravel content was the same, the velocity and runoff rate of two-dimensional plane slope were larger than those of three-dimensional cone slope. (3) The denudation rate of two-dimensional plane slope presented a change process of "stable, decreasing and stable fluctuation" with the runoff time. The denudation rate of three-dimensional cone-shaped slope presented a process of "augmented, stable fluctuation". (4)The amount of erosion per unit area increased first and then decreased with the increase of gravel contents. With the same gravel content, the erosion amount of two-dimensional plane slope was larger than that of three-dimensional cone slope.