《西洲曲》与南北朝长江军事分界线——兼论《西洲曲》的创作时代

《西洲曲》爱情故事与南北朝历史地理背景及其变动密切相关，当长江南北之间交通自由时，江北男子曾到江南与江南女子相恋，后来长江南北之间交通断绝，双方不能见面、通信，唯有隔江相思。南北朝之间边境防守严密，禁止通行，故可称之为南北朝军事分界线。南北朝时，只有梁末至陈代前期（549～573）及陈代后期（579～589），长江两次成为南北朝军事分界线。《西洲曲》爱情故事的历史地理背景，当为梁末至陈代前期或陈代后期江北地区属北时的长江下游地区。《西洲曲》声律有局部粘对，亦与梁陈时期近体诗声律发展到局部粘对甚至全部粘对相一致。从《西洲曲》的历史地理内容及声律看，《西洲曲》当是梁末至陈代的作品（549～589）。

Ballad of Xizhou and Military Demarcation Line of Northern and Southern Dynasties——Also on the Creation Time of Ballad of Xizhou

The love story in Ballad of Xizhou is closely related to the context of history and geography, as well as the changes in the Southern and Northern Dynasties. When there was traffic freedom between the North and South of Yangtze River, a man from north fell in love with a woman to the south of the river. And then the Yangtze River traffic between North and South was cut off, so the lovers could not meet and had to write to each other. The border between Northern and Southern Dynasties was prohibited to pass, which could be called the military demarcation line in the Southern and Northern Dynasties. In Northern and Southern Dynasties, Yangtze River had become the military demarcation line twice between the North and South during the period from the late-Liang to the early-Chen （549-573） and the late-Chen （579 - 589）. As for the historical and geographical background of the love stories in Ballad of Xizhou, it should be in the lower reaches of the Yangtze River, which belonged to the northen area during the phase from the late-Liang to the early-Chen or the late-Chen. There is a phenominon of partial Niandui in the tones of Ballad of Xizhou, which is align with the tone development of modern-style poetry to partial or even all Niandui in Chen. Based on the history and geography content as well as the law of tone, it can be dedueed that Ballad of Xizhou is the work written in the period from late-Liang to Chen.