This study evaluated the damage of red blood cells (RBC) during exposure to impulsive vibration. Five peak accelerations were investigated:​ 50, 100, 200, 250 and 300 k m/s². All impulsive vibrations had a repetition rate of 1/s. Each vibration was given for 10, 20 and 30 minutes to each blood sample which was put in a container whose inside was coated by heparin. After the vibration exposure the damage of RBC was analyzed. Each vibration was found to cause damage to RBC in all duration, which was confirmed by the microscopic study. Of five impulsive vibrations with three exposure duration, the largest damage was obtained in the vibration exposure with peak acceleration of 300 k m/s 2 for 30 minutes, followed by the exposure with 300 k m/s² for 20 minutes. The higher the peak acceleration and the longer the exposure duration, the more the damage of RBC. It was suggested that the damage of RBC in vitro depended on both peak acceleration and exposure duration of impulsive vibration.