We present the first Hinode/EIS observations of 5 min quasi-periodic oscillations detected in the transition region and corona at the foot-point of a corona] loop. The oscillations are characterized by a series of wave packets with nearly constant period, typically persisting for 4-6 cycles. There is an in-phase relation between Doppler shift and intensity oscillations, indicating upwardly propagating slow magnetoacoustic waves in the loop. We find that the oscillations detected in the five coronal lines are highly correlated, and the amplitude decreases with increasing temperature. These oscillations may be caused by the leakage of the photospheric p-modes through the chromosphere and transition region into the corona, which has been suggested as the source for intensity oscillations previously observed by TRACE. The temperature depen-dence of the oscillation amplitudes can be explained by damping of the waves traveling along the loop with multithread structure near the footpoint.
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