Length-weight relationships (LWRs) are reported for nine fish species belonging to four families from the upper reach of the Gan River, one of the main tributaries of the Yangtze River, China. A total of 807 specimens were collected from April 2016 to July 2017. Fishes were both sampled using a backpack electrofishing unit and collected from local fish markets that using various fishing gears such as electrofishing boats, gillnets (mesh sizes: 1-12 cm), hooks, and benthic fyke nets (mesh sizes: 0.5 cm and 0.7 cm). The fish species were Siniperca undulata (Fang & Chong, 1932), Pseudogobio vaillanti (Sauvage, 1878), Sarcocheilichthys parvus (Nichols, 1930), Barbodes semifasciolatus (Gunther, 1868), Spinibarbus hollandi (Oshima, 1919), Gobiobotia meridionalis (Chen & Cao, 1977), Pseudobagrus albomarginatus (Rendahl, 1928), Pseudogastromyzon changtingensis (Liang, 1942), and Pseudogastromyzon fangi (Nichols, 1931). The a values for the nine species varied between 0.0056 and 0.0366, the b values ranged from 2.333 to 3.318, and r(2) values from.952 to.994.