The characteristics of concentration variations for dust, O3, and its precursors in Busan, South Korea were analyzed on the basis of pollution data from 19 stations during 2005. The objectives of these analyses were (i) to observe the ozone precursor concentrations under various conditions, (ii) to examine the mechanism of high [O3] episode development, (iii) to examine the formation of photochemical aerosols, (iv) to observe the spatial distribution of high [O3] occurrence over time, and (v) to observe the spatial distributions of temperature and wind speed over the whole area of Busan on high [O3] episode days. The ratio of initial [NO2] to initial [NO], O3 dosage, and O3 formation/hazard potential were established as relevant parameters on which to base allocation of monitoring stations according to each regional type, and criteria based on these parameters were determined for reallocating stations over the Busan area according to various regional types based on monitoring purposes. It was found that the current allocations of stations for investigating photochemical pollution do not reflect the areas where high O3 occurs and areas where it is desirable to measure O3 and its precursors flowing out of the target area. Therefore, based on these criteria, reallocated monitoring stations according to each regional type were suggested.