中文摘要：

基于每日的 NCEP 分析数据， OLR 和卫星降雨数据，在 2004 的华南海夏季风(SCSSM ) 的活动的特征被分析。Theresults 比正常和紧张比正常强壮证明 SCSSM 的建立很少迟了。由向西北和平的副热带的高度的地点影响了，它比正常向北方并且向西多， SCSSM 在华南海区域主要是活跃的。在那里存在的明显的 intraseasonal 摆动和 SCSSM 的二个重要时期，一个人是 about20-30 天和另外的大约 40-50 天。潮湿的交通被专注于华南海和西北太平洋区域，减少向北方交通并且在南部的中国导致干旱。

英文摘要：

Based on daily NCEP reanalysis data, OLR and satellite rainfall data, the characteristic of the activities of South China Sea summer monsoon（SCSSM） in 2004 were analyzed. The results showed that the establishment of SCSSM was little later than normal and the intensity was stronger than normal. Influenced by the location of the northwest Pacific subtropical high, which was much northward and westward than normal, SCSSM was active mainly in the South China Sea areas. There existed obvious intraseasonal oscillation and two significant periods of SCSSM, one was about 20-30 days and the other about 40-50 days. The transportation of moisture was concentrated on the South China Sea and the northwest Pacific regions, reducing the northward transportation and resulting in drought in southern China.