Special aspects of the dynamics of the stratospheric sudden warming 1970--1971 are investigated by using daily data. During the period of December 1970 until March 1971, several atmospheric levels are analyzed in order to demonstrate the development of the major stratospheric warming. The wave-1 and wave-2 propagation, the mean zonal wind and temperature, and the horizontal eddy fluxes of momentum and heat are considered, and the development of the zonal wind is analyzed on the basis of the mean momentum equation. It turns out that the equatorward eddy momentum fluxes at high latitudes associated with planetary waves were crucial in effecting the zonal wind reversal as was discussed by O'Neill and Taylor <1979> for the warming of January 1977. In addition, the present paper indicates that a negative meridional phase gradient entailing an equatorward momentum flux propagated from the troposphere up to the stratosphere.