The physiological performance of animals can be affected by many factors, of which the body mass is an important one. In order to investigate effects of body mass on energy metabolism and thermal tolerance in Qingbo (Spinibarbus sinensis), we firstly measured the resting metabolic rate (RMR), maximum metabolic rate (MMR), metabolic scope (MS, MMR-RMR), and excess post-exercise oxygen consumption (EPOC) of fish with different body mass (1, 10, 25, and > 50g groups) at 25℃. Then the critical thermal minimum (CT_min), lethal thermal minimum (LT_min), critical thermal maximum (CT_max), and lethal thermal maximum (LT_max) of fish were measured. The RMR, MMR, MS, and EPOC increased significantly with body mass of Qingbo (P < 0.05). The relationship between ln[RMR (mg h^-1 fish^-1)] and ln[body mass (g)] was described as y=0.796x-1.123 (R²=0.983, n=32, P < 0.001), while y=0.834x-0.322 (R²=0.985, n=32, P < 0.001), y=0.849x-0.030 (R²=0.972, n=32, P < 0.001), and y=1.137x-2.099 (R²=0.943, n=32, P < 0.001) were adopted to illustrate the relationships between metabolic parameters including ln[MMR (mg h^-1 fish^-1)], ln[MS (mg h^-1 fish^-1)], ln[EPOC (mg fish^-1)], and ln[body mass (g)], respectively. These relationships indicated that all parameters of metabolic traits were following allometry models with body mass, and these scaling exponents for metabolic traits (i.e., the slope of equation) were significantly greater than 2/3 (P < 0.05). Moreover, the RMR, MMR, and MS of unit body mass Qingbo significantly decreased (P < 0.05), however, that of EPOC distinctly increased with body mass (P < 0.05). The results may be related to the increased metabolic demands of swimming with the increase of body mass. The relationships between CT_min and CT_max (℃) and body mass (g) were described as y_CTmin=0.0007x²+0.0459x+9.191 (R²=0.685, n=16, P_quadric < 0.001) and y_CTmax=-0.0003x²+0.0202x+39.198 (R²=0.293, n=16, P_quadric=0.083), respectively. While those between LT_min and LT_max (℃) and body mass (g) were described as y_LTmin=0.0003x²+0.0351x+6.581 (R²=0.657, n=16, P_quadric=0.005) and y_LTmax=-0.0003x²+0.0204x+40.285 (R²=0.392, n=16, P_quadric=0.041), respectively. These relationships indicated that the thermal tolerance of the intermediate body mass Qingbo was the strongest, which was possibly related to the variant developmental stages and temperature acclimation period in the experimental fish.