Meteorological measurements were carried out in the basin of Cheong-Kwan located Yang-San near Pusan city, from Oct. 30 to Nov. 1, 1988. According to the measured data, we verified the close relationship between the variation of nocturnal inversion layer and the meteorological elements. The nocturnal inversion layer by radiative cooling in this site extends up to 130 meters or so. And the nocturnal jet appears just above or at the top of the inversion layer, and the stronger of the prevailing wind blows, and the lower of the jet level appears. Some meteorological features such as heating, cooling etc., began to change in or in the slightly higher level of the inversion layer, when they are formed, reinforced and disappeared. And the air in the basin preserves its character because it is not affected by local scale air flow.