Tzu is the typical representative in Sung Dynasty literatures. The Tzu style is different from poetry and “Chu” (a type of verse for singing, which emerged in Southern Sung and Jin dynasties and became popular in Yuan Dynasty). The application of “Ling-tzu” is characteristic. The book “Tzu Yuan” written by Chang yen in Sung dynasty indicated that empty words are suitable to be used in the sentence structure of Tzu. Shen Yi-fu’s “Yueh Fu Chih Mi” also approved that empty words could be used in “Tzu-tiao”. That is to say, both of them insisted using the empty words properly. Therefore, later generations called the empty words in the beginning of the sentences “Ling-tzu”, “Ling-tiao” or “Ling-tiao-tzu” to emphasize its function of being the leading word. In this thesis, first, the researchers made a thorough inquiry of “Ling-tzu”, including differentiating and analyzing some terms such as “Chen-tzu”, full words, and empty words appearing in the beginning, in the middle and at the endo f a sentence. Also, the researchers expounded the definition of “Ling-ztu” and traced to the sourced of the “Ling-tzu” in the sentence structure of poetry. Second, by mainly checking Tang Kuei-chang’s “Chuan Sung Tzu”, “Tzu Pu”, which was edited by the order of Emperor Kang-His in Ching Dynasty, and Wan Shu’s “Tzu Lu”, the researchers enumerated and analyzed the real application of “Ling-tzu” in Sung Tzu and covered different dimensions: the number of words, examples and tones of “Ling-tzu”; the number of words, sentence structures, the skills of arranging words; the different application cases in different Tzu styles; some “Tzu-tiao” using “Ling-tzu” in special place; the fluency, coherence and transition of :Ling-tzu.”