The x values and electrical conductivities of the nonstoichiometric compounds $WO_{3-x}$ have been measured in the temperature range from 350 to 700$^{circ}C$ under oxygen partial pressure of $2{ imes}10_{-1};to;1{ imes}10_{-5}$ atm. The enthalpy of the defect formation shows an endothermic process, and the oxygen pressure dependence of the defect formation or 1/n varies from -1/5.2 to -1/5.9. The activation energy and 1/n value for the electrical conductivity are 0.24~0.29 eV and -1/4.3~-1/7.6, respectively. The Tungsten Oxide as a n-type semiconductor has predominently defect model of singly charged oxygen vacancy at low temperature, and of doubly charged oxygen vacancy at high temperature.