We have attempted direct observation of the light-driven rotation of a FoF(1)-ATP motor. The FoF(1)-ATP motor was co-reconstituted by the deletion-δ subunit of FoF(1)-ATP synthase with bacteriorhodopsins (BRs) into a liposome, The BR converts radiation energy into electrochemical gradient of proton to drive the FoF(1)-ATP motor. Therefore. the light-driven rotation of FoF(1)-ATP motor has been directly observed by a fluorescence microscopy using a fluorescent actin filament Connected to β-subunit as it marker of its orientation. The rotational torque value of the Fo motor was calculated its 27.93 1 1.88 pN nm. The ATP motor is expected to be a promising rotary molecular motor in the development of nanodevices. Published by Elsevier Inc.