A conventional liquid scintillation analyzer is typically equipped with two photomultiplier tubes to distinguish the signals of disintegration events from the noise of photomultipliers. However, commercially available liquid scintillation analyzers are not designed to provide signal output from each individual photomultiplier. Considering this limitation, the liquid scintillation analyzer was assembled with NIM modules so that it could generate a bifunctional scintillation spectrum from the two photomultipliers. The pulse height of the bifunctional spectrum obtained increased with decreasing the quenching. This change was consistent with the principles of the liquid scintillation counting.