Focal adhesions (FAs) are integrin-based, multiprotein structures that form links between the intracellular actin cytoskeleton and extracellular matrix (ECM). Vinculin is a major FA component and has been proposed to stabilize FAs in a force-dependent manner. While it is known that interaction of vinculin with F-actin is critical for vinculin‘s function, how vinculin associates with dynamic actin networks has remained unclear. At the cell periphery, the retrograde actin flow (a continuous centripetal movement of the actin network) is widely observed in adherent cells. By using Sigle-Molecule Speckle (SiMS) microscopy, we found that vinculin in lamellipodia exhibits retrograde flow-associated motion. To clarify how vinculin interacts with the lamellipodial actin network, we examined molecular motions of wild-type vinculin and three kinds of vinculin mutants: constitutively active, lacking F-actin binding, and weak talin binding mutants, respectively. We also observed that vinculin on matured FAs observed by SiMS microscopy exhibits both flowing and stationary fractions. Our findings suggest the following three points: (1) vinculin associates with the lamellipodial actin network mainly via binding to talin. (2) the vinculin-talin complex moves through actin retrograde flow over mature FAs without linkage between F-actin and integrins. (3) Vinculin-talin may form a pre-bound complex in a force-independent manner. These findings, employing direct observation of vinculin and actin at the molecular level, provide new insights into the molecular mechanisms of focal adhesion dynamics.