A new type of liquid membrane oscillator in which non-ionic surfactant is the key component was designed in a U type tube and monitored by a pair of Pt electrodes. The fundamental composition is 1. 0% emulsifier OP (aq) / n-butanol: nitrobenzene = 1: 5 (V/ V) /0. 5mol. dm-3NaCl(aq). The molecular formula of emulsifier OP is C8H17 O(CH2CH2O) 10H. The mechanism and influence factors were studied by replacing component, changing concentration, adding additive, comparison between different experimental apparatus and auxiliary experiment. The oscillatory mechanism is repetitive formation and abrupt destruction of interface membrane of the surfactant, induced by hydrogen bond between n-butanol and emulsifier OP.