Time-integrated X-ray continuum spectra measured with spherical bent quartz crystal and CCD in aluminum wire array Z-pinches, provide electron temperature by fitting the continuum slope. More data obtained for fitting and markedly reduced influence of line radiation by removing the data superimposed with line spectra, make the temperature in hot core region of plasma more reliable. In experiment of shot No. 09076, the core temperature is around 250 eV, ranging from 241 eV to 258 eV at a 95% confidence level.