Typically, the summer over Korea is characterized by heavy rainfall mainly connected with Changma front in June and July (and/or sometimes concerning about occasional activities of Typhoon) and a hot spell for a month from the late July to the mid-August. However, the Korean peninsula has experienced abnormal heavy rainfall period after the Changma period in recent years. In summer 2002, there appeared an abnormal heavy rain period on August after the withdrawal of Changma. Heavy rainfall was recorded mostly over the whole nation during 12 days from 4 to 15 of August in 2002, and the area-mean precipitation amount reached to about 400 mm that is 30% of annual total. In this study, we attempt to understand the causes for the abnomal flooding in August of 2002 by conducting numerical experiments as well as analyzing the observed data. During the heavy rainfall period, it is found that the upper ridge around the northern part of Mongolia and the strong positive anomaly around Okhotsk sea are characterized, showing a pattern of blocking. Consequently, the deep upper trough becomes stagnant over Korea between the two highs. In addition, large amount of the low level moisture is transported from south to north throughout Korean peninsular along the edge of Northern Pacific High stepped back slightly. For the analyses of the causes, it is found that the SST warm anomalies over the tropical eastern Pacific and the area of the northern Pacific in the mid-latitude are directly responsible for the synoptic setting in East Asia. However, soil moisture is found to play an important role in initiating and maintaining the heavy rainfall over the Korean peninsular. The analyses of the numerical results with a regional climate model also support the role of the soil moisture in China in late spring for the summer rainfall over Korea.