Two genetic closely related cyprinids-hook snout carp (Opsariichthys bidens) and pale chub (Zacco platypus) with incompletely overlapped habitats in Wu River-were selected as experimental models to investigated the difference of hypoxia tolerance and locomotor performance between two fish species and whether the possible exist difference be related with the distributed habitats. We first measured the critical oxygen tension (P_crit), aquatic surface respiration (ASR) and loss of equilibrium (LOE) as the hypoxia indicators. Then we measured the critical swimming speed (U_crit) and active oxygen consumption rate (MO_2active) at different dissolved oxygen level (8.0, 4.0 and 2.0 mg/L, respectively) at (25.0±1.0) ℃. The P_crit of hook snout carp (2.44±0.20) mg/L were significantly higher than that of pale chub (1.86±0.10) mg/L (P=0.031). However, the dissolved oxygen level at which 50% fish performing ASR (P=0.023) and LOE (P=0.004) in hook snout carp (ASR: (1.23±0.16) mg/L; LOE: (0.84±0.01) mg/L) were significantly lower than those in pale chub (ASR: (1.97±0.11) mg/L; LOE: (0.97±0.02) mg/L). Both the U_crit and MO_2active of hook snout carp and pale chub reduced significantly with the decreased dissolved oxygen level (P=0.008 and P=0.002, respectively); The swimming oxygen consumption rate of hook snout carp and pale chub increased exponentially with increasing swimming speed. However, the swimming speed-oxygen consumption curve became relatively flat at lower testing dissolved oxygen levels. The swimming speed-oxygen consumption curve of hook snout carp was more gently compared with that of pale chub at the dissolved oxygen level of 4.0 mg/L. The present study demonstrated that there were significant differences in both hypoxia tolerance and swimming performance between hook snout carp and pale chub which may be crucial to its survival in the field. The difference may be due to the difference of ecological habit and hence different preferred habitats of two fish species.