The effects of salinity fluctuation on the growth, molting and energy budget of juvenile Litopenaeus vannamei was investigated at the temperatures of 20, 25, and 30°C. Salinity fluctuation regimes were set in different amplitudes of ± 0, ± 5, ± 10 and ± 15 gL⁻¹ from a control salinity of 20 gL⁻¹. After a 48-day feeding trial, the lowest survival occurred at a salinity fluctuation of ± 15 gL⁻¹ for each temperature investigated. The best growth of shrimp was obtained at salinity amplitudes of ± 5-10 gL⁻¹ at 25 and 30°C. The salinity fluctuation influenced food conversion efficiency but not food intake. The shrimp maintained at salinity amplitudes of ± 5-10 gL⁻¹ expended most of the energy for growth and spent less energy on respiration and excretion at 25 and 30°C. Therefore, salinity fluctuating amplitudes of ± 5-10 gL⁻¹ result in higher growth rates than constant salinity conditions (20 gL⁻¹) through enhanced feed assimilation and reduced energy loss in respiration and excretion.