漢代所確立的以大鴻臚為主、客曹尚書為輔的中央外交管理體制，到了魏晉南北 朝演變為以尚書主客曹為主、鴻臚寺為輔的管理格局。曹魏、西晉時期的客曹尚書放太康中 撤銷，此後由原為其下屬之主客曹負責外交管理。主客曹主要職責為外交行政管理，負責外 交文書及有關政令之起草、發布、收受；同時也承擔外交接待事務，負責接待來使、禮賓安 排、交涉談判及降附與僑民管理等。西晉、北魏時主客曹多曹並設，南、此主客曹分別負責 南、北方諸國外交事務，左右主客曹則與封爵事務有關。對於主客郎的人選要求，除了儀容 蘊藉、口齒辯捷等對外交官員的一般要求之外，南北朝時期尤重博學高才，這是由於北方胡 族政權的漢化，其學術文化水平提高，南北之間進入以學術文化交鋒為特色的外交競爭新階 段，雙方以學術文化相陵轢，故需選拔博學高才之士以充其任。與此同時，常根據這一需要 而臨時選派適宜人選以它官兼插主客郎以接待來使。

　　　　　In the diplomatic and administrative system developed during the Han Dynasty, the Royal Ceremonial Bureau 大鴻臚 was the highest institution, and the Higher Bureau of Guests 尚書主客曹 (subordinate to the central government administration) was an auxiliary body. Duringthe Wei, Jin and Northern and Southern Dynasties, however, this order was reversed-the Higher Bureau of Guests became the highest institution, and the Royal Ceremonial Bureau was relegated to an auxiliary position. The Higher Bureau of Guests that existed in the early Wei andWestern Jin was dismantled during the Taikang period, when its formerly subordinate institution, the Bureau of Guests, became responsible for diplomatic administration. The Bureau's functions included the drafting and handling of diplomatic documents and government decrees, receiving of foreign envoys and guests, diplomatic negotiation and administration of alien affairs. During the Western Jin and Northern Wei, the Bureau of Guests added on a number of subordinate bodies, including the Northern Bureau of Guests and Southern Bureau of Guests (responsible for diplomatic affairs), as well as the Left Bureau of Guestsand the Right Bureau of Guests (responsible for the conferring of noble titles). The criteria used in selecting diplomatic envoys included extensive learning, elegant bearing and eloquent speech. These qualities were particularly important during the Northern and Southern Dynasties, because as the northern government of the Hu nationality became Sinicized, their cultural level rose, and academic learning became an increasingly important factor in diplomatic competition between the North and South.