Distributions of current and chemical tracers along two hydrographic sections across Ring 94S, a Kuroshio detached eddy in the South China Sea, were studied. Results suggest that while currents on its offshore side maintained quasi geostophic, a balance was no reach on its onshore side. It is then suggested that interaction Ring 94S with the slope might play an important role that could break down the quasi geostrophic balance and caused deformation of the current field. 18 O distribution supports previous discussion that water mass inside the ring is of Kuroshio origin. Distributions of chemical tracer reveal strong “stirring effect” at the edge of Ring 94S, which may play an important role in vertical exchange across the thermocline. Distributions of current and chemical traces along two hydrographic sections across Ring 94S, a Kuroshio detached eddy in the South China Sea, were studied. Results suggest that while currents on its offshore side maintained quasi geostophic, a balance was no reach on its onshore side. It is then suggested that interaction Ring 94S with the slope might play an important role that could break down the quasi geostrophic balance and caused deformation of the current field. 18 O distribution supports previous discussion that water mass inside the ring is of Kuroshio origin. Distributions of chemical tracer reveal strong “stirring effect ” at the edge of Ring 94S, which may play an important role in vertical exchange across the thermocline.