Data of Automatic Weather Stations (AWS) and Wind Profile Radar (WPR) from 2006 to 2007 in north and south slopes ofthe Himalayas in Mt.Everest region are used to understand the characteristics of local circulations, and WRF model is used to simulate and better understand the wind observations in this region.Observations in the north of Mt.Everest were conducted in the research field of the Qomalangma Station for Atmospheric and Environmental Observation and Research (QOMS)-Chinese Academy of Sciences, which is located in the downstream of Rongbuk Valley at an altitude of 4270m, and that in the south were at an Italian site for Asia Brown Cloud observation, ABC-Pyramid (Bonasoni et al, 2002), located in Khumbu Valley in Nepal at an altitude of 5079m.Results indicate local circulations in the two valleys are quite different due to the impact of monsoon circulation.In the south, there is typical mountain-valley wind system found, while in QOMS, mountain-valley wind exists only in the morning.It is found strong up-valley wind in the southem slope reaches the northern slope along deep valley in east of Mt.Everest, and becomes well-known down-slope wind in the downstream of Rongbuk Valley, which appears regularly in the afternoon during most time of a year, especially after the beginning of monsoon in the southern slope.Large scale northward air transportation over Himalayas also exist during this period.