Plants evergreen. Rhizome thick, creeping, ca. 3 cm in diam., apex with brown lanceolate scales; fronds approximate. Fertile frond up to 1.5 m; stipe green, shorter than lamina, up to 5 mm in diam., sparsely scaly, grooved on adaxial side; lamina 2-pinnate below apex, deltoid or ovate-deltoid, up to 90 × 80 cm, apex acuminate; pinnae ca. 11 pairs, alternate or subopposite, ascending, slightly asymmetrical with slightly broader basiscopic side, lower pinnae broadly elliptic-lanceolate, shortly stalked, basal pairs largest, up to 50 × 20 cm, with basal pinnules remarkably shortened; pinnules up to 10 pairs, alternate, spreading, slightly asymmetrical, lanceolate or falcate and lanceolate, up to 11 × 4 cm, base broadly cuneate or subtruncate, sessile, pinnatifid to pinnatisect, or 2-pinnate, apex acuminate or long acuminate, occasionally acute or rounded; basal acroscopic pinnules shorter, close to rachis, basal basiscopic pinnules oblique; pinnule lobes up to 10 pairs or more, alternate or subopposite, slightly ascending, elliptic, margin obtuse-crenate or pinnatilobate, apex rounded; veins somewhat visible abaxially, not prominent adaxially, pinnate with up to 8 pairs of veinlets, veinlets mostly forked or pinnate, rarely simple. Lamina thinly herbaceous when dry, dark colored, shiny adaxially, costae and midribs with thin multicellular hairs. Sori shortly linear or elliptic, up to 5 pairs per lobe, inframedial, close to midribs. Sori reniform in equatorial view, perispore prominent, with few rugate projections.

Cornopteris major is similar to C. pseudofluvialis in gross morphology of frond, but it differs by the tall fertile fronds ca. 1.5 m, pinnules up to 10 × 3 cm, sori shortly linear or elliptic (not orbicular), and lamina abaxially with multicellular thin hairs, lacking glandular hairs.

● Evergreen broad-leaved forests, beside streamlets; 2100-2600 m. SE to SW Yunnan.