During the period from July 1st to the end of November 1970, a survey on air pollution and noise level was made in Seoul, Pusan and Taegu, the three largest cities in Korea. Each city was divided into 4-6 areas : the industrial area, the semi-industrial area, the commercial area, the residential area, the park area and the downtown area. Thirty eight sites were selected from each area. A. Method of Measurement : Dustfall was measured by the Deposit Gauge Method, sulfur oxides by PbO2 cylinder method, suspended particles by the Digital Dust Indicator, Sulfur dioxide (SO2) and Carbon Monoxide (CO) by the MSA & Kitakawa Detector and the noise levels by Rion Sound Survey meter. B. Results: 1. The mean value of dustfall in 3 cities was 30.42 ton/km2/month, ranging from 8.69 to 95.44. 2. The mean values of dustfall by city were 33.17 ton/km2/month in Seoul, 32.11 in Pusan and 25.97 in Taegu. 3. The mean values of dustfall showed a trend of decreasing order of semi-industrial area, downtown area, industrial area, commercial area, residential area, and park area. 4. The mean value of dustfall in Seoul by area were 52.32 ton/km2/month in downtown, 50.54 in semi-industrial area, 40.37 in industrial area, 24,19 in commercial area, 16.25 in park area and 15.39 in residential area in order of concentration. 5. The mean values of dustfall in Pusan by area were 48.27 ton/km2/month in semi-industrial area, 36.68 in industrial area 25.31 in commercial area, and 18.19 in residential area. 6. The mean values of dustfall in Taegu by area were 36.46 ton/km2/month in downtown area, 33.52 in industrial area, 20.37 in commercial area and 13.55 in residential area. 7. The mean values of sulfur oxides in 3 cities were 1.52mg SO3/day/100cm2 PbO2, ranging from 0.32 to 4.72. 8. The mean values of sulfur oxides by city were 1.89mg SO3/day/100cm2 PbO2, in Pusan, 1.64 in Seoul and 1.21 in Taegu. 9. The mean values of sulfur oxides by area in 3 cities were 2.16mg SO3/day/100cm2 PbO2 in industrial area, 1.69 in semi-industrial area, 1.50 in commercial area, 1.48 in downtown area, 1.32 in residential area and 0.94 in the park area, respectively. 10. The monthly mean values of sulfur oxides contents showed a steady increase from July reaching a park in November. 11. The mean values of suspended particles was 2.89mg/m3, ranging from 1.15 to 5.27. 12. The mean values of suspended particles by sity were 3.14mg/m3 in Seoul, 2.79 in Taegu and 2.25 in Pusan. 13. The mean values of noise level in 3 cities was 71.3 phon, ranging from 49 to 99 phon. 14. The mean values of noise level by city were 73 phon in Seoul, 72 in Pusan and 69 in Taegu in that order. 15. The mean values of noise level by area in 3 cities showed a decrease in the order of the downtown area, commercial area, industrial area and semi-industrial area, park area and residental area. 16. The mean values of noise level by area in 3 cities indicated that the highest level was detected in the downtown area in Seoul and Taegu and in the industrial area in Pusan. 17. The daily average concentration o sulfur dioxides (SO2) in 3 cities was 0.081 ppm, ranging from 0.004 to 0.196. 18. The daily average concentration of sulfur dioxides by city were 0.092 ppm in Seoul, 0.089 in Pusan and 0.062 in Taegu in that order. 19. the weekly average concentration of carbon monoxides (CO) was 27.59 ppm. 20. The daily average concentration of carbon monoxides by city were 33.37 ppm. in Seoul, 25.76 in Pusan and 23.65 in Taegu in that order. 21. The concentration of SO2 and CO reaches a peak from 6 p.m. to 8 p.m. 22. About 3 times probably the daily average concentration of CO could be detected in the downtown area probably due to heavy traffic emission in comparison with that in the industrial area. 23. As for daily variation of the concentration of SO2 and CO it was found that the concentration maintains relatively higher value during weekdays in the industrial area and on the first part of the week in the downtown area.