Magnetohydrodynamic (MHD) waves play a significant role in the processes of the solar wind acceleration and the coronal heating. Based on the in situ measurements of the?WIND spacecraft, some MHD waves in the quiet solar wind are identified with two criteria: (1) the correlation coefficients between velocity and magnetic field perturbations?( and ) and between thermal pressure and magnetic pressure perturbations?(δpt and δpb), and (2) the dispersion relations of MHD waves. A preliminary statistics of those MHD modes is also achieved by selecting and analyzing the WIND data of 42,279 samples (45050.4 hr) in the 23rd solar cycle. It is found that the time fraction of Alfvén waves is 8% in this period,?while the existence time of slow waves is 3.4%,?and the fast wave is rare. The statistical result also shows that the Alfvén waves have a higher time fraction in fast solar wind, while the occurrence of slow waves is higher in moderate-speed?solar wind. This work will provide more clues to understanding MHD activities in the solar wind, as well as the studies of solar wind acceleration and heating.
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