Disclosed are ultrasonic wireless power transmitter and receiver apparatuses, and a method for wireless charging thereof. A method for wireless charging according to the present disclosure includes: transmitting, by an ultrasonic wireless power transmitter apparatus, an wakeup signal to an ultrasonic wireless power receiver apparatus; calculating, by the ultrasonic wireless power transmitter apparatus, a charging time according to a charging status information received from the ultrasonic wireless power receiver apparatus; generating, by the ultrasonic wireless power transmitter apparatus, an ultrasonic signal, amplifying the generated ultrasonic signal to predetermined voltage and thereafter; charging, by the ultrasonic wireless power transmitter apparatus, the ultrasonic wireless power receiver apparatus for the calculated time and thereafter; and determining, by the ultrasonic wireless power transmitter apparatus, whether secondary charging is to be performed according to a charged status information received from the ultrasonic wireless power receiver apparatus.