Abstract: As a common phenomenon in nature, lightning can influence living environment and production extremely. With continuous field lightning observation tests and model experiments, the understanding of lightning process is making a great progress, especially for cloud-to-ground (CG) lightning progression process. The spatial propagation of lightning shows characteristics of randomness, which make lightning unpredictable and lightning protection difficult.The influence of different lightning spatial configurations on CG lightning process is studied, including the location of stroke points, the length of upward leader, the tip location of downward leader when upward leader trigger, form of lightning attachment process. Based on existing model, a region near to the ground is highlighted and the spatial resolution is improved. A 2-dimension model of CG lightning progress process is developed to simulate different lightning spatial configurations by changing random parameters via using the finite difference method. It shows that the difference of lightning spatial configurations will make the location of stroke points different, and random lightning spatial configurations make the length of upward leader random. The range of length of upward leader is 77 m to 609 m, and it concentrates on 100 m to 200 m. Besides, statistical results show that the length of upward leader triggered from building is longer than that triggered from the ground. It also makes the tip location of downward leader when upward leader trigger distribution regularly. The tip location presents ellipsoidal distribution over the building. Also, different lightning spatial configurations will affect the form of CG lightning attachment process. Simulation results emerge three lightning attachment process forms and all can be verified by field lightning observations. All these outcomes show that lightning spatial configuration plays an important role in affecting CG lightning process.In addition, according to a series of statistical analysis, it shows that the length of downward leader and the length of upward leader near the ground have certain linear correlation. The other factors of lightning have little correlations, such as the length of downward leader near the ground and striking distance, the length of upward leader and lightning horizontal extent.