Abstract: The kinematic relational expression in the near zone of an explosion was introduced. Energy consumption in elastic medium was considered when the surface of radial crack was formed. By analyzing the distortion and failure for the near zone of the explosion, the dynamics calculation sketch was proposed by adopting different main stress functions. Through researching the characteristic of each zone development and the change relation, the coefficients of compression and failure radii about RPC concrete under contact explosion were obtained. Comparison between the test results and the empirical formulas shows the practicability and reliability of the proposed formula.