Based on the concentration equation of smoke screen onflow diffusion, the basic characteristics of smoke cloud onflow motion are analyzed. And the motion characteristics and diffusion trends of several kinds of smoke material smoked at near-ground are analyzed through the experiments at the states of smoke grenade static explosion and smoke generator spraying in order to build the relationships among smoke source characteristic parameters, atmosphere environment and effect parameters through determining diffusion variance and coefficient at a certain experimental condition in the future and the practical application to evaluate the performances such as smoke screen shield and airborne endurance.