Abstract: In the containment analysis of nuclear power plant, containment scaling analysis could be used to confirm the important phenomena of containment cooling system and demonstrate the sufficiency of test data. Based on the design basis accident (DBA) of passive nuclear power plant, the scaling analysis method was used to quantify the effect of heat and mass transfer characteristic of liquid drop to mass, energy and RPC. The effect of containment cooling system phenomena to containment pressure response can be confirmed by this scaling analysis.