We study experimentally the temperature spectra of inteal friction (IF) and relative dynamic modulus (RDM) in a foamed Zn-Al eutectoid alloy. The specimens with macroscopic pores (0.5-1.0mm) were prepared in an air pressure infiltration process. The damping behaviour of the foamed Zn-A1 eutectoid alloy is characterized by IF. The IF and RDM measurements at a maximum surface shear strain of 20 x 10-6 have been made by using a multi-function inteal friction apparatus at frequencies of 0.5, 1.0 and 3.0Hz from room temperature to the equilibrium eutectoid isotherm of 277°C, while continuously changing the temperature cycle. At low frequency,an IF peak is observed in the IF temperature curve. The IF peak is of a grain boundary, which is associated with the diffusive flux on a crystalline boundary between the like-phases of Al/A1. Its activation energy has been calculated to be 1.10 ± 0.06 eV and the pre-exponential factor γ0 is 10-14 s in the IF measurements.