Composition dependence of Ag‐photodoping in x GeO2‐(100–x)GeS2 glasses has been studied. The doping rate decreases with an increase in x, and becomes negligible at x ≥ 60. This photodoping disappearance can be related with transformation from percolated GeS2 networks in the heterogeneous oxy‐chalcogenide glasses to isolated nano‐scale clusters. Remarks on photodoping processes and overall composition dependences are also given. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)