Abstract: Based on a great quantity of data, this paper mainly analyses the major flow patterns, the characteristics of sea-land breeze and the feature of vertical distribution of prevailing wind direction and average wind speed in case of winter monsoon and summer monsoon in the low latitude, in view of atmospheric diffusion, the vertical distribution of the wind direction and the wind speed within the boundary are divided into 4 and 5 categories separately, of which the frequency is given. Finally, the influence of various flows on the atmospheric diffusion is analyzed in combination with the characteristics of the turbulence.