Abstract: Thirteen species of Araphidiales (Bacillariophyta) are newly recorded from the Hengduan Mountains, including Odontidium truncatum (Mayer) Luo & Wang nov. comb., Distrionella germainii (Reichardt & Lange-Bertalot) Morales, Bahls & Cody, Tabellaria flocculosa var. linearis Koppen, Fragilariforma bicapitata var. genuina Ta kin & Açikgöz, Fragilariforma javanica (Hustedt) Wetzel, Morales & Ector, Fragilaria aquaplus Lange-Bertalot & Ulrich, Fragilaria boreomongolica Kulikovskiy, Lange-Bertalot, Witkoxski & Dorofeyuk, Fragilaria sandelii Van de Vijcer & Jarlman, Fragilaria heatherae Kahlert & Kelly, Fragilaria crassirhombica Metzelitin, Lange-Bertalot & Soninkhishig, Fragilaria pennsylvanica Morales, Fragilaria misarelensis Almeida, Delgado, Novais & Blanco, and Ulnaria macilenta Morales, Wetzel & Rivera. Herein, we describe in detail the morphological characteristics of the newly recorded species, as well as their geographic distribution, habitat information, and physicochemical indicators. The morphological characteristics of the newly recorded species and similar species are also discussed.