Embodiments of the present invention provide a method of manufacturing a pixel unit, in which only a single patterning process and a single doping process are performed on a polysilicon layer so as to form heavily doped regions of a thin film transistor and a lower electrode of a storage capacitor respectively, thereby reducing numbers of photolithography and masking processes required to manufacture a LTPS-TFT, shortening time periods for development and mass production, and reducing complexity of processes as well as monitoring difficulty, and decreasing the production cost. The present invention further provides a pixel unit manufactured according to the method, an array substrate and a display device including the same.