Kinesin is a motor protein that plays important physiological roles in intracellular transport, mitosis and meiosis, control of microtubule dynamics and signal transduction. Kinesin converts chemical energy from ATP into mechanical force. Kinesin family is classified into some subfamilies. Some species of kinesin derived from vertebrate have been well studied. However, not so many studies for kinesins of plants have been done yet. Recently, the genome sequences of rice were completed. Bioinformatical analyses revealed that at least 41 kinesin-related proteins were encoded on the rice genome. In this study, we focused on the two rice kinesins; 1. O12 that has a calponin homology domain, 2. K23 that belongs to At1 subfamily in kinesin-7. The cDNAs of the kinesin motor domain was subcloned into expression vector pET and transformed into E. coli BL21 (DE3). kinesin motor domains were expressed and purified by Co-NTA column. The biochemical characterizations of the two rice kinesins were studied. The microtubule-dependent ATPase activity of the two rice kinesins motor domains were 30∼60-fold lower than that of conventional kinesin. Kinetic analyses using stopped-flow demonstrated that ATP binding to O12 in the absence of microtubule was extremely slow compared with that of conventional kinesin. While, ATP binding to K23 was not accelerated by microtubule. Furthermore, interestingly ATPase activity of O12 in the absence microtubule regulated by actin. The O12-tail fused with GFP was observed to localize in the actin filament in the onion cell. The two plant specific rice kinesin O12 and K23 were shown to have unique enzymatic properties.