High entropy alloys (HEAs), which contain five or more principle elements, have attracted increasingly attention in science and technology applications due to its superior mechanical performance. Recent theoretical studies suggest that the chemical arrangement of the elements on the crystalline lattice is not fully random, but partially ordered, and it probably is a short ranged. Recently, effects of the short-range order (SRO) on the material properties, such as the stacking fault energy, have been investigated. However, the formation process and stability of SRO are still unclear. Here, we use kinetic Monte Carlo (kMC) method and study the vacancy diffusion driven short-range ordering process, temperature dependent SRO formation rate, and thermodynamic stability of constructed SRO. We find that, the stability of SRO is critically related to the interatomic interactions and temperature. Below a critical temperature, SRO is starting to be constructed along the vacancy diffusion pathway.