Hourly concentrations of PM₁, PM_2.5 and PM₁₀, were investigated at Gangneung city in the Korean east coast on 0000LST October 26~1800LST October 29, 2003. Before the intrusion of Yellow dust from Gobi Desert, PM₁₀(PM_2.5, PM₁) concentration was generally low, more or less than 20 (10, 5) g/m³, and higher PM concentration was found at 0900LST at the beginning time of office hour and their maximum ones at 1700LST around its ending time. As correlation coefficient of PM₁₀ and PM_2.5(PM_2.5 and PM₁, and PM₁₀ and PM₁) was very high with 0.90(0.99, 0.84), and fractional ratios of PM₁₀-PM_2.5)/PM_2.5((PM_2.5-PM₁)/PM₁) were 1.37~3.39(0.23~0.54), respectively. It implied that local PM₁₀ concentration could be greatly affected by particulate matters of sizes larger than 2.5m, and PM_2.5 concentration could be by particulate matters of sizes smaller than 2.5 m. During the dust intrusion, maximum concentration of PM₁₀(PM_2.5, PM₁) reached 154.57(93.19, 76.05) g/m³ with 3.8(3.4, 14.1) times higher concentration than before the dust intrusion. As correlation coefficient of PM₁₀ and PM_2.5(vice verse, PM_2.5, PM₁) was almost perfect high with 0.98(1.00, 0.97) and fractional ratios of PM₁₀-PM_2.5)/PM_2.5((PM_2.5-PM₁)/PM₁) were 0.48~1.25(0.16~0.37), local PM₁₀ concentration could be major affected by particulates smaller than both 2.5 m and 1 m (fine particulate), opposite to ones before the dust intrusion. After the ending of dust intrusion, as its coefficient of 0.23(0.81, - 0.36) was very low, except the case of PM_2.5 and PM₁ and PM₁₀-PM_2.5)/PM_2.5((PM_2.5-PM₁)/PM₁) were 1.13~1.91(0.29~1.90), concentrations of coarse particulates larger than 2.5 m greatly contributed to PM₁₀ concentration, again. For a whole period, as the correlation coefficients of PM₁₀, PM_2.5, PM₁ were very high with 0.94, 1.00 and 0.92, reliable regression equations among PM concentrations were suggested.