Abstract: Based on the equations for the conservation of mass, momentum, and energy together with the theory of plane shock wave and thermodynamics, a debris cloud model was proposed to characterize the debris cloud produced by normal impact of spherical projectile on thin plate shield. Characteristics of debris cloud calculated by using the proposed model are in agreement with the experimental results. Under different conditions, calculated results of characteristics for debris cloud by using the proposed model show the following conclusions. (1) The center-of-mass and spread velocities of debris cloud increase with the increase of impact velocity and projectile diameter, and decrease with the increase of shield thickness, and spread half angle increases with the increase of impact velocity and shield thickness and decreases with the increase of projectile diameter. (2)The change curves of velocity and spread half angle of debris cloud have similarities. (3)Under the determination of projectile and shield material, percentage by mass of materials in different phase states has relation only to impact velocity of projectile for the debris cloud loaded by shock wave. These conclusions are consistent with the experimental results.