The thermoelectric power, S, of the Chevrel phase compounds PbMo//6S//8 and EuMo//6S//8 were measured on sintered pellets from liquid helium temperature to room temperature. In PbMo//6S//8 S is positive and is a sum of electron diffusion (S//e) and phonon drag (S//p//h) parts. From S//e, using the rigid band model of Mott, the slope of the density of states curve is calculated. The result is compared with existing band structure calculation. In EuMo//6S//8 the thermoelectric power shows a sharp rise at around 100K which is the temperature at which a structural transformation takes place. The thermoelectric power reverses sign at 92K and 33K.