In this study, we designed and developed an ultrasonic transducer which can measure urine volume based on the estimation of distance between the interior-wall and posterior-wall of bladder. Measurement of urine volume is a way to help patients with urinary incontinence by detecting the amount of urine before the urine is released from the bladder. With the results of this experiment, we can measure the urine volume more accurately and also develop an incontinence preventive system. This study can help patients with urinary incontinence and enuresis to live longer, healthier lives.