3 5 Cl NQR frequencies and spin-lattice relaxation time (T 1 Q ) and 1 H NMR relaxation times (T 1 H ) in a H-bonded three molecular system, chloranilic acid-1,4-diazine (1:2) were measured to reveal H-motions in a symmetric two H-bonds in solid. A single 3 5 Cl NQR frequency observed implies that the time-averaged structure of chloranilic acid is roughly monovalent in accordance with pK a values in both acid and base. T 1 H temperature dependence was explained by a single relaxation mechanism due to the correlated H-transfer in two H-bonds, while that of T 1 Q yielded two relaxation processes. One of these undetected by 1 H NMR was explained by the uncorrelated H-transfer.