We investigated the effects of water temperature, salinity, and dissolved oxygen (DO) content on the swimming ability of juvenile tiger puffer , cm/s) and maximum swimming speed (was determined under different temperatures (15.2℃, 20.2℃, 25.6℃ and 30.4℃), salinities (0, 10, 20, 32 and 40), and DO content (2.14 mg/L, 4.10 mg/L, 5.81 mg/L and 7.36 mg/L). The both increased as water temperature ( increased from 13.12 to 29.07 cm/s; increased from 17.51 to 37.38 cm/s. The relationship between could be interpreted with quadratic models, as: ²=0.995 (T-12.27, U_max also increased as DO was increased from 2.14 to 7.36 mg/L: increased from 16.43 to 33.65 cm/s. The relationship between DO and could be interpreted with quadratic models, as: =0.995 (+11.10DO-3.919, <0.01). The salinity challenges had no significant effects upon of the juvenile tiger puffer (>0.05). Temperature is known to strongly influence the contractile properties of muscles. According to "compression of the recruitment order theory", recruiting all of a fish's aerobic fibers at a lower speed results in reduced sustainable performance. The effects of temperature on the physical properties of water may also affect fish swimming ability. The viscosity of water decreases as temperature increases, and this may increase the swimming efficiency of fish in warmer waters. The swimming ability of juvenile tiger puffer might be limited by the cardiorespiratory system in response to hypoxia as a result of impaired functioning of the oxygen transport and exchange system. Furthermore, as another response to hypoxia, increases in respiratory frequency to improve the absorbance of oxygen must evoke an additional energy cost to the animal. The absence of any significant changes in the of the juvenile tiger puffer following the various salinity challenges could be a direct result of this species' exceptional ability for maintaining plasma homeostasis and water balance in the tissues. In natural environments, lower temperatures and hypoxia would reduce the swimming ability of juvenile tiger puffer and thereby weaken their predation and/or predator-avoidance capacity. These findings increase our understanding of the biology and ecology of the tiger puffer, and may be useful for enhancing stocks of this near-threatened species.