The application of Ultrasonic Velocity Profile monitor (UVP) to the measurements of a velocity vector field is presented. The two-dimensional vector fields were obtained for two different flow configurations; the one is a recirculating flow in a square cavity and the other is for a flow at the 180° turning end of the double coaxial tube type loop. In the first experiments, UVP measured the one dimensional velocity distributions instantaneously, namely Vx(x) at various positions Y and Vy(y) at positions X, and thus we obtained two two-dimensional velocity distributions as Vx(x,y) and Vy(x,y). Those two distributions forms a velocity vector field. The results showed a recirculating primary vortex and two corner vortices very clearly. Furthermore, a various flow characteristics such as distributions of vorticity and stream function were estimated, by which a comparison of flow parameters were made with the ones reported earlier. In the second experiment, the flow patterns were studied for two different geometries and various flow parameters and used in a practical design work of geometry optimisation. From both experiments, it was shown that the UVP is quite efficient and effective in obtaining velocity vector fields and it can provide an alternative to the conventional flow visualisation technique.