A nanostructure surface layer was produced on low carbon steel and commercially pure titanium using high-speed rotating wire-wheel deformation (HRWD). The microstructural features of the surface layer were systematically characterized by cross-sectional optical microcopy observations, transmission electron microscopy, and microhadness measurement was conducted along the depth from top surface layer to matrix of the samples. The results show that nearly equiaxed nanocrystalline layer is formed on the surface of the low carbon steel and pure titanium, in which the average grain size is about 8 nm and 15 nm respectively. The microhardness of the top surface is enhanced obviously compared with that of the coarse-grained matrix.