Fraxinus mandschurica (Manchurian Ash) is a species of Fraxinus native to northeastern Asia in northern China, Korea, Japan and southeastern Russia. Also known as 'Chinese Oak'.
It is a medium-sized to large deciduous tree reaching 30 m tall, with a trunk up to 50 cm in diameter. The leaves are 25-40 cm long, pinnate compound, with 7-13 leaflets, the leaflets 5–20 cm long and 2–5 cm broad, subsessile on the leaf rachis, and with a serrated margin. They turn to a golden-yellow in early autumn, and the tree is usually early to change color. The flowers are produced in early spring, before the new leaves, in compact panicles; they are inconspicuous with no petals, and are wind-pollinated. The fruit is a samara comprising a single seed 1-2 cm long with an elongated apical wing 2.5-4 cm long and 5-7 mm broad.
It is closely related to Fraxinus nigra (Black Ash) from eastern North America, and has been treated as a subspecies or variety of it by some authors, as F. nigra subsp. mandschurica (Rupr.) S.S.Sun, or F. nigra var. mandschurica (Rupr.) Lingelsheim.
The spelling of the species name is disputed; some (e.g. the Flora of China) cite mandschurica, while others (e.g. USDA GRIN) cite mandshurica.