The effects of boundary mixing on a continuous gravity current (a plume) propagating along an incline were investigated using a laboratory experiment. Boundary mixing was generated by oscillating the incline along its plane. It was observed that when the background turbulence is strong, such typical characteristics of the gravity current as the ''raised-head'' structure and the sharp front disappear. Quantitative measurements on the frontal velocity, density structure, and the thickness of the gravity current were made, and their dependencies on the intensity of turbulence at the boundary are presented. ¿ American Geophysical Union 1991