The characteristics of power-law conductivity sigma(omega) proportional to omega(a) (0 < a < 1) of one single monolayer of merocyanine-arachidic acid mixed system sandwiched between aluminum electrodes (Al) have been investigated in the dark with different molar mixing ratios. The admittance of the sandwich cell was measured for frequency ranges 1 x 10(-4) Hz less than or equal to omega/2(pi) less than or equal to 3 x 10(-1) Hz, 50 Hz less than or equal to omega/(2 pi) less than or equal to 100 kHz at room temperature. The power index a of admittance for Al/merocyanine:arachidic acid = 1:2/Al junction is appreciably smaller than that for Al/pure arachidic acid/Al junction.