A structure-explosives coupled analysis is sometimes needed in defence area. Direct explosion analysis with structure deformation can gives accurate informations. However, the direct analysis of explosion with structure deformation require large computation costs due to huge impedance difference of explosive and structure. In many cases, fast and fairly good analysis results are preferred than late accurate results. In that cases, pre-defined pressure function during explosion can be used instead of direct explosion analysis. The explosion pressure is a function of distance from the ignition point, explosive mass, and time. In this study, the explosive pressure function is generated using explosion analysis results.