The variations of TSP concentrations observed at Air Quality Monitoring Stations(AQMSs) in Seoul were analysed from 1986 to 1993. And those of Yellow Sand period were investigated to find out the characteristics between normal and Yellow Sand period. The TSP concentrations have begun lower than 150.mu.g/m$^{3}$ annual mean concentration at Gwanghwamun, Hannam-dong, and south river region since 1989, and air quality in Seoul was improved in 1991, but polluted again in Hannam-dong, and Seongsu-dong in 1992. Yellow sand phenomena of 1990 and 1993 were selected for case study. During the whole period in 1990, the TSP concentrations were exceeded over 300.mu.g/m$^{3}$, which is the upper limit of 24 hour concentration, at the center of city such as Mapo, Gileum-dong, sinseol-dong. But in 1993, the TSP concentrations got lower than 24 hour concentration, and air quality was highly improved.