This study was carried out to understand the regional contribution of Particulate Matter (PM) emissions from East Asia (82° ∼149°E, 18°∼53°N) to Seoul during high concentration period in February 2014. In the paper, The WRF(Weather Research and Forecasting) - SMOKE(Sparse Matrix Operator Kernel Emissions) - CMAQ (Community Multi-scale Air Quality) modeling system was used for meteorological field generation, emissions preparation and air quality simulations, respectively. The CMAQ version 5.0.2 with Decoupled Direct Method (DDM) was used to analyze levels of contributions over Seoul. In order to validate model performance of the CMAQ, calculated PM and its chemical species concentrations were compared to observations at Seoul super site. Model predictions match relatively well with the daily and hourly variations of observed PM10 and PM2.5. The predicted PM10 and PM2.5 concentrations, however, had a tendency of underestimation. The discrepancies are due to uncertainties of emission inventories, meteorological data and CMAQ model itself. The high PM concentration in Seoul was induced by stationary anticyclone over the West Coast of Korea during 24 to 27 February. The DDM in CMAQ was used to analyze the contributions of East Asia on Seoul during this PM episode days. PM10 concentration in Seoul area is contributed by China industrial and urban region of 39.77% ~ 53.19%, South Korea of 15.37% ~ 37.10%, and North Korea of 9.03% ~ 18.05%, respectively. As time goes by the contribution of China is decrease, South Korea''s contribution has increased. These indicate that PM10 concentrations in Seoul area during the episode period are dominated by long-range transportation from China region as well as domestic sources. It was also found that the largest contribution region in China were Shandong peninsula during the PM event period.