In this study, researchers use ultrasonic wave for extraction of Bromelain from pineapple waste.  By comparing the results of traditional extraction methods and ultrasonic extraction methods. To study the optimal condition for ultrasonic extraction methods. By using three parts of pineapple waste such as peels, stalks and corks in the Pattavia pineapple oriinaled from Prachuap Khiri Khan Province.  The results of the  experiment show that the ultrasonic extraction is better than the traditional extraction.  Moreover, ultrasonic extraction of the pineapple cork has the highest protein amount (107.47 mg/mL), followed by peels (106.27 mg/mL),  and stalks (45.53 mg/mL) respectively. And the period of time for the optimal conditions is studied by ultrasonic extraction viz at 10 and 20 minutes. It is found that the enzyme activity at 10 minutes is better than 20 minutes and the best activity id found to be 0.1339 Units/mL. The results of this study show that the use of ultrasoinc waves is appropriate to extraction of Bromelain from pineapple waste.