Doppler shifts of the solar Fe line 630.15 nm relative to the terrestrial O2 line 630.2 nm were determined at many positions on the solar disk to investigate the rotation of the solar plasma and locate large-scale plasma motions. The spectrum was measured by a self-scanning linear photodiode array with 128 diodes; and average rotation velocity of (2.881 plus or minus 0.027) microrad/s was found at the solar equator in September 1978, and large-scale velocity pattern occurred between plus 40 and minus 30 deg in latitude with a period of 45 deg in longitude during Sept. 6 to 13, 1978.