Abstract: The effects of ultrasonication on L-carnitine extraction were studied, and the technological parameters were optimized. Bovine livers were treated by perchloric acid method assisted with ultrasonic to extract L-carnitine. Based on the single factor tests for ultrasonic power, ultrasonic time and solid-liquid ratio, a three-variable quadratic general rotary unitized experimental design was applied to optimize the parameters for ultrasonic extraction of L-carnitine. The results indicated that the influencing factors were ultrasonic power, solid-liquid ratio and ultrasonic time in order. The optimum extraction parameters are as follows: ultrasonic power 437 W, ultrasonic time 15 min and solid-liquid ratio 1:5 g/mL. Under these conditions, the L-carnitine yield was 38.37 mg/kg. The study show that ultrasonic technology in the extraction process is applicable for L-carnitine preparation.