Liu (2006) derived analytical solutions for turbulent boundary layer flows under transient long waves. His analytical solutions were obtained with the assumption that the nonlinear inertia force was negligible in the momentum equations. Using Liu's general solutions, we examine the turbulent boundary layer flow characteristics under a solitary wave. It is found that while the horizontal component of the fluid particle velocity outside the boundary layer always moves in the same direction of wave propagation, the fluid particle velocity near the bottom inside the boundary layer reverses the direction as the wave decelerates. Consequently, the bottom stress also changes the sign during the deceleration phase.