Actin based motor protein was purified from Chara corallina using high performance liquid chromatography. Sodium dodecyl sulfate gel electrophoresis showed that the molecular weight of the main band was about 230kDa. Although the molecular weight was quite similar to that of the heavy chain of muscle myosin (myosin II), the motor protein was soluble at low ionic strength and antibody raised against the main band did not recognize smooth muscle myosin. The antibody also did not recognize the actin based motor protein from lily pollen tube. The motor protein translocated fluorescently labeled actin filaments at about 25μm/s in the in vitro motility assay. The MgATPase activity of the motor protein was enhanced by F-actin about 150 fold. Calcium ion concentration had little effect on both the motor activity and the actin activated MgATPase activity.