The ruthenium complex, (8-(2-diphenylphosphinoethyl)aminotrihydroquinolinyl) (carbonyl)(hydrido)ruthenium chloride, exhibited extremely high efficiency toward the coupling cyclization of -aminoalcohols with secondary alcohols. The corresponding products, pyridine or quinoline derivatives, are obtained in good to high isolated yields. On comparison with literature catalysts whose noble metal loading with respect to γ-aminoalcohols reached 0.5 – 1.0 mol% for Ru and the lowest record 0.04 mol% for Ir, the current catalyst achieves the same efficiency with a loading of 0.025 mol% Ru. The mechanism of acceptorless dehydrogenative condensation (ADC) was proposed on the basis of the DFT calculations; meanwhile the reactive intermediates were determined by GC-MS, NMR and single crystal X-ray diffraction. The catalytic process is potentially suitable for industrial application.