Combining materials with one-dimensional (1D) nano-wire/nanotubes and two-dimensional (2D) lamellar flakes leads to three-dimensional (3D) hierarchical nanocomposites with unexpected properties for unique applications.Up to now, CNTs can be controllably synthesized on various kinds of matrices to directly fabricate hierarchical nanocomposites.Compared with traditional procedures, the in situ nanocomposite fabrication strategy is quite easy-operating and low cost.