AbstractWe present results on the stellar population properties of massive galaxies at z = 0.7 based on deep, medium-resolution IMACS spectra for a sample of ~ 70 galaxies in the ECDFS with M_* > 10¹⁰M_⊙. The age–mass and stellar metallicity–mass relations for the population as a whole have a similar shape as the local relations over the probed mass range, but offset to ages younger by ~ 4 Gyr and metallicities lower by ~ 0.13 dex. Quiescent galaxies alone have stellar ages and metallicities consistent with passive evolution onto the local quiescent galaxies relations. The evolution in metallicity is driven by star-forming galaxies. However a significant fraction of massive star-forming galaxies have metallicities comparable to those of local quiescent galaxies. If quenched at z < 0.7 they can provide the necessary population to reproduce the scatter in age and metallicity of local quiescent galaxies.