The two-dimensional h-BN/MoS2 van der Waals heterojunction, was fabricated, and is stacked by h-BN and MoS2 monolayers, which are combined together by van der Waals forces. We have measured the valence band offset (VBO) of h-BN/MoS2 heterojunction by X-ray photoelectron spectroscopy (XPS) experimentally. The measurement result of VBO is 0.24 ± 0.15 eV and the conduction band offset (CBO) is calculated to be 3.99 ± 0.15 eV, revealing a type-I band alignment of h-BN/MoS2 heterojunction. Anderson’s affinity rule has verified the accuracy of the measurement result of VBO.