InN layers were directly grown on Ge substrate by plasma-assisted molecular beam epitaxy (PAMBE). The valence band offset (VBO) of wurtzite InN/Ge heterojunction is determined by X-ray photoemission spectroscopy (XPS). The valence band of Ge is found to be 0.18 ± 0.04 eV above that of InN and a type-II heterojunction with a conduction band offset (CBO) of ∼ 0.16 eV is found. The accurate determination of the VBO and CBO is important for the design of InN/Ge based electronic devices. © 2011 Elsevier B.V. All rights reserved.