The decomposition of silver chromate complex with 1, 10 phenanthroline has been studied by TG/DTG/DTA method and X-ray diffraction analysis. Intermediate decomposition products have been isolated and characterized. The thermolysis of Agz(phen)zCr04 occurs in the two major stages: Agz(phen)x"CrO4" as a product of the first stage and various mixtures of silver, silver chromate and silver metachromite as the final residue. The comparison of the decomposition process of the complex with that of parent Ag2CrO4 indicates that the presence of ligand changes thermal behaviour of the latter.Syntheses and spectral properties of silver chromate complexes with heterocyclic bases (HB) have been studied recently [1].We have extended this work using thermogravimetric and DTA analyses on Ag2(bpY)2CrO4 and Ag2(phen)2CrO4 [2]. This paper reports details on the thermal behaviour of the phen complex together with the analysis of the intermediate products of its decomposition. As various Cr(VI) compounds were found to be precursors of widely adopted chromia catalysts [3,4], M(HB)xCrO4 type complexes can be also interesting from this point of view.