Abstract: The containment pressure response analysis, which is important to verify the passive containment cooling system (PCS) design, requires a better understanding of the effects of various phenomena during the design basis accident (DBA). A sensitivity analysis on containment pressure response was performed by using sampling with coupled DAKOTA and WGOTHIC codes. The effect of various phenomena in the phenomena identification and ranking table (PIRT) on containment pressure was evaluated quantitatively by using the partial correlation coefficient. The results show that such phenomena as mass/energy release, initial conditions inside containment, and evaporation/condensation, significantly affect containment pressure. The sensitivity evaluation is of significance on advanced passive plant containment design, containment safety analysis, and safety review.