Abstract: The effects of nitric acid concentration, rare earth concentration, the other main salts concentration and temperature on the ultrasonic wave velocity in the simulated high-level liquid waste are studied. The results show that the effects of main salts such as Na, Al, Fe are obvious and the effects of nitric acid, rare earth and temperature are not obvious. The difference of the ultrasonic wave velocities in 30 % TRPO-kerosene pre- and post-extraction can be ignored. The effect of temperature on the ultrasonic wave velocity in 30 % TRPO-kerosene is obvious. The experimental results by using ultrasonic technique in the stirred cell also show that the relative deviations are within ± 10 % when the volume fraction of organic phase is in the range of 5%～ 60 %.