This work examines the characteristics of the flow patterns, velocity properties, and vortex shedding in the wake of a finite swept-back wing at low Reynolds numbers. The airfoil of the wing is a NACA 0012, and the sweep-back angle is 15 deg. The smoke-wire technique is used to visualize the flow patterns and evolution of vortex shedding. Five characteristic smoke-streak flow modes, namely, the attached surface flow, instability wave in wake, vortical wake, separation from near leading edge, and bluff-body wake are classified according to chord Reynolds numbers and angles of attack. Additionally, flow topologies of these surface flow modes and the time-dependent wake evolution processes are analyzed from the separatrices, alleyways, and critical points. Moreover, the velocity field around the wing section is quantified by the particle image velocimeter. Finally, the velocity vector field, streamline pattern, vorticity contour, turbulence kinetic energy, and frequency of these five flow modes are presented and discussed.