The low level atmospheric observation carried out to investigate magnitude, formation and dissipation of nocturnal surface inversion layer, also to survey relation to each meterological parameter in inversion layer at Pusan power plant for Oct. 13, 1996. As coastal area, the surface inversion layer height was relatively high(186m), and after sunset unstable layer formated from surface to around 40m, and the inversion layer was left still in the upper layer. The surface inversion layer dissipated at 0920LST perfectly. The layer that strong inversion layer was formated, showed steep variation of potential temperature and wind speed and relative humidity.