Abstract: The use of ultrasonic vibration in acetic acid extraction of Ca2+ from wollastonite increased obviously the extraction ratio of Ca2+ ion. When acetic acid extraction was carried out with 200—300 mesh wollastonite，weight fraction of acetic acid 25%，the frequency of ultrasonic 32 kHz，60 oC，3 h，the extraction rate of Ca2+ was 43.0 %. Under the same conditions it was 27.9 % without ultrasonic vibration，the relative efficiency increased by 54 %. When the wollastonite particle was larger in size，the extraction rate of Ca2+ with ultrasonic vibration was much higher than that without ultrasonic vibration. A higher extraction rate of Ca2+ was also obtained when the extraction reaction was carried out at a lower temperature. Therefore，energy consumption was reduced markedly when ultrasonic vibration was used.