The effect of residual solvent on the carrier transport in poly(methylphenylsilane) films which were formed from toluene and tetrahydrofuran solutions and dried in different conditions has been investigated by a time-of-flight technique. The dependence of hole drift mobility on the electric field and temperature has been analyzed in a framework of the superimposed disorder and polaron effect. It is found that no parameter but the polaron binding energy has a strong relation with an amount of the residual solvent. The polaron binding energies of 0-126 meV in addition to the native polaron binding energy of 80 meV for polysilane are discussed as solvent-related values.