The four-probe technique is used to measire the electric conductivity of polyacetylene doped with iodine. For dopant concentration ranging from 1.0 to 8.3 mol% in cis-(CH)x, the obtained conductivity values for different temperatures are consistent with the variable-range hopping model. The mechanisms of the temperature dependence of the ESR spin magnetic susceptibility and line width for low iodine concentrations are studied.