Abstract: The doppler spectra of ionospheric irregularities have been analyzed by usingfive years HF doppler records at Wuhan Ionospheric Observatory. Usually, thedoppler spectra of spread F are always diffusive, while the spectra of Es showsmooth straight line daytime, and become diffusive in the night. The meandoppler spread of scattering echoes is 2 or 3 times more than that of normalechoes. Moreover, one type of slant striated doppler spectrum associated with thedrift of ionized clouds in Es or spread F is also discussed in this paper.