﻿AbstractWood-inhabiting fungi are abundant in China, but their distribution is uneven, with more fungi in southwest China and fewer fungi in northwest China. During the investigation of wood-inhabiting fungi in Xinjiang, we collected a large number of specimens. Eight specimens growing onPiceaschrenkianawere collected from Tianshan Mountains, and they were described as two new species inCeriporiopsisandSiderabased on morphological characters and molecular evidence.Ceriporiopsistianshanensisis characterized by a cream to salmon-buff pore surface, larger pores measuring 1–3 per mm, and broadly ellipsoid basidiospores 5–6.5 × 3–4 μm.Sideratianshanensisis characterized by annual to perennial basidiocarps, measuring 15 mm thick, pores 5–7 per mm, cream to rosy buff pore surface, and allantoid basidiospores 3–3.5 × 1–1.4 µm. Detailed illustrations and descriptions of the novel species are provided.