A stability to the spreading solvent, which is acetonitrile, benzene, chloroform and acetonitrile-benzene(1:1, v/v) of (3-Alkyl benzimidazdium)-TCNQ(1:2) complex was investigated by UV-visible spectrometer and was confirmed stabilized on acetonitrile, acetonitrile-benzene(1:1, v/v) for five hours. Using Ultra pure water as subphase for Langmuir-Blodgett(LB) films, it was achived successively to fabricate the Y-type LB films of (3-Alkyl benzimidazolium)-TCNQ(1:2) complex. For the identification of (3-Alkyl benzimidazolium)-TCNQ(1:2) complex, UV-visible spectra was recorded on HP 8452A spectrometer.