In this paper, the finite element program LS-DYNA was used to simulate the dynamic response of RC column with different constraints subjected to blast pressure. Through analyzing the five group columns with fixed end as well as one end fixed and one end simply supported, the maximum middle displacement and its relation with T/Tω were obtained. Thereby the dynamic factor of the column under blast pressure was acquired. Consequently the displacement response spectrum curve of the column was drawn. The results provide reference value to the design and protection of the RC column.