It is commonly hypothesized that On Ci PoetryT5 was written by Li Qingzhao in Northern Song Dynasty (960A. D.1127 A. D. ), but "Northern Song Hypothesis" lacks sufficient evidence, for there is something wrong with the existing vidence and the reasoning process. On CiPoetry should be written after the Southward Movement of Northern Song Dynasty for the following reasons: 1. On CiPoetry criticized " Sounds of Country Extinguishing", which is in conformity with the social background after the Southward Movement of Northern Song Dynasty; 2. Melodic Norms suggested in On CiPoetry were gradually perfected at the end of Northern Song Dynasty; 3. On CiPoetry did not come out until 1167; 4. At the end of Northern Song Dynasty, Su Shi and Huang Tingjian is a very sensitive topic, and it is impossible for Li Qingzhao to write On Ci-Poetry concerning Su Shi and Huang Tingjian because of her own unique identity; and 5.It is likely that On CiPoetry was written to reflect the realities of CiPoetry Field in Southern Song Dynasty ( 1127 A. D.—1279 A.D.) .