The paper presents the results of investigations in thermoelectric power of pregraphitic carbons in the temperature range from 20 to 200K. The thermoelectric power of pregraphitic carbon has been shown to follow the model of sequential connection of islets with metallic conductivity, islets with hop conductivity of variable hop length and islets with hop conductivity of constant hop length. The description of thermoelectric power in islets of metallic conductivity requires the dependences of major mechanisms of charge carrier scattering on the temperature to be taken into account. The parameters of pregraphitic carbon electronic structure have been calculated from the experimental results on temperature dependence of electrical resistivity.