Abstract:The Lancang-Mekong River is an international river, and is one of the richest areas of fish biodiversity in the world. There is a total of 37 Nemacheilid species in the Lancang River basin in China. Due to the difficulty in classification and identification of Nemacheilidae, there are still some species that have not been discovered, described or accurately identified in the Lancang River basin. Many surveys of fish diversity were conducted during 2015 to 2019 in the Lancang Jiang basin in both Puer and Xishuangbanna prefecture, Yunnan Province. Among collected fish species, there are three nemacheilid fish species which never been recorded from China before; The important character of the collected fish specimens were measured (Table 1), and the morphological characters were compared with relevant literatures. They were identified as Nemacheilus longistriatus, Schistura nudidorsum and S. latidens, respectively. Nemacheilus longistriatus is the only loach species of Nemacheilus distributed in China, and is herein described from main stream of Langcang River in Menghan Town (Fig. 1). It is distinguished from its congeners in Southeast Asia by its colour pattern consisting of an obvious bold black midlateral stripe and 9﹣12 dark saddles along back (Fig. 2). S. nudidorsum is described from Nan’a River in Jinghong City and Nanju River, a tributary of Nanlan River in Menghai County (Fig. 3), and is distinguished by scales present in the predorsal area, 8﹣11 faint dark bars on flank, narrower than or equal to interspaces, in the predorsal area usually wider at its upper extremity and usually not meeting its homologues on the dorsal midline, and lateral line completed (Fig. 4). S. latidens was collected from the main stream of Weiyuan River in Fengshan Town (Fig. 5), and it differs from any other species of genus Schistura in having a broad, short, often exposed processus dentiformis on the upper jaw, mouth width approximately equal to 2/3 of the head width, 7﹣10 relatively regular dark black stripes on body, and a complete basial caudal bar (Fig. 6). In this paper, the three newly recorded fishes of Lancang River are described, which has certain guiding significance for the identification of Lancang River fish species, and provides scientific basis for the investigation and conservation of fish resources in Lancang River.