Self-assembly of two-dimensional (2D) structures from functional molecules is of great scientific importance. Herein, using a typical linear conducting polymer, polyaniline as building blocks, 2D single crystalline microplates are successively produced. The structure of 2D microplates is clearly defined by selected area electron diffraction, X-ray diffraction, and Raman spectroscopy. Owing to the anisotropic arrangement of linear conjugated PANI molecules, the microplate shows a typical anisotropic electrical transport property.