Recent X-ray Observations of Blazars

Recent progress in the X-ray study of TeV blazars observed with ASCA, RXTE, Beppo SAX, and XMM-NEWTON is reviewed in this paper.The most important aspects emerged from the temporal and spectral analysis of the X-ray data, including power spectral density, structure function, inter-band time lags, shifts of synchrotron peak energies, and spectral evolution are focused.The physical implications inferred from these new results are also briefly discussed.