Length‐weight relationships were determined for three fish species (Platytropius yunnanensis He, Huang & Li, 1995, Schizothorax lantsangensis Tsao, 1964 and Schizothorax yunnanensis Norman, 1923) from southwestern China. Specimens were collected using gillnets (20 × 2 m, mesh‐size 5 mm; soaking depth: 50–150 cm; exposure time: 10 hr/day) and electroshock fishing techniques quarterly from May 2016 to June 2017. Standard length (SL, nearest 0.1 cm) were determined as well as weight (nearest 0.1 g). The a values ranged from 0.01385 (S. lantsangensis) to 0.04155 (P. yunnanensis), the b values ranged from 2.68 (P. yunnanensis) to 2.98 (S. lantsangensis) and the coefficient of variation (r2) ranged from 0.957 (P. yunnanensis) to 0.963 (S. yunnanensis).