Length-weight relationships are presented for five fish species collected in the Angqu River, the headwater of the Lancang River in China. The following species were examined: Schizothorax lantsangensis, Ptychobarbus kaznakovi, Schizopygopsis anteroventris, Triplophysa stolickai and Triplophysa stenura. Specimens were collected at five sampling sites along the Angqu River over a two-year period between April 2017 and December 2019, using different fishing gear. The values of parameter a varied between 0.005 and 0.011 while those of parameter b ranged from 2.847 to 3.09. The coefficients of determination (r 2 ) were higher than .95. Based on the records in FishBase, the results of the present study represent the first report of LWRs for these five species in the Angqu River, with new total lengths also reported for two species (T. stolickai and T. stenura). Due to the unique location of the Angqu River, the data from the present study are expected to be valuable not only for monitoring these fish species, but also for developing and assessing appropriate management measures.