The phase relationship in the Gd-Ti-Al ternary system at 500degreesC was investigated by powder X-ray diffraction (XRD), differential thermal analysis (DTA), optical microscopy and electron probe microanalysis (EPMA) techniques. The 500degreesC isothermal section of this ternary system consists of 14 single-phase regions, 27 two-phase regions and 14 three-phase regions. At 500degreesC, the maximum solid solubilities of Ti in Gd2Al, Gd3Al2 and GdAl2 is 2.0 at.%, 3.5 at.%, 16.3 at.%, respectively and that of Gd in Ti, Ti3Al, TiAl is less than 1 at.%.