Using the temperature profiles retrieved from the Mars Climate Sounder (MCS) instrument onboard Mars Reconnaissance Orbiter (MRO) satellite between November 2006 and April 2013, we studied the seasonal and interannual variability of Quasi-Stationary Planetary Waves (QSPWs) in the Martian middle atmosphere. The QSPW amplitudes in the Southern Hemisphere (SH) high latitudes are significantly stronger than those in the Northern Hemisphere (NH). Seasonal variation with maximum amplitude near winter solstice of each hemisphere is clearly seen. The vertical structure of the QSPW in temperature shows double-layer feature with one peak near 50Pa and the other peak near 1 Pa. The QSPW in geopotential height is clearly maximized in the region between two temperature peaks. The maximum amplitude of QSPW for s=1 is ∼8–10 K in temperature and ∼1 km in geopotential height in the SH high latitudes. The maximum amplitude at the SH high latitudes in Mars Year (MY) 31 is ∼2 K stronger than those in other MYs, suggesting the clear interannual variability. We compared the satellite results with those obtained from the Mars Climate Database (MCD) simulation version 5.0; a reasonable agreement was found. The MCD simulation further suggested that the variability of dust might partially contribute to the interannual variability of QSPW amplitude.