In this study, high-frequency ultrasonic generations of massive nanobubbles are developed using several piezoeletric transducers for bio-applications. Experimental parametric studies are performed on how the nanobubble size and concentration are affected by various parameters such as the size of piezoelectric transducer types, input frequency, and generation time. The size distributions of generated nanobubbles are measured by nanoparticle tracking analysis device (Nanosight NS300). The average size of ultrasonic cavitation bubbles is around 80 ~ 110 nm with the concentration of 10⁸/ml.