The introduction theme (first 10 bars) of the Tchaikovsky’s symphony no. 5 is the main subject of this thesis. In the first chapter, we described the background of this symphony, and later, studied the introduction theme in the second chapter which, includes its “fate idea”, source, name, spirit, affections (Emotional expression) and cyclical form. With respect to the detail of the form, we analyzed the phrasing, material and orchestration, and then used the theory of harmony and interval to explain the affections. The appendix is an interview with Mr. Ting-Yu Wu who is the concertmaster of National Symphony Orchestra since 1987. We talked about the 5th symphony, Tchaikovsky’s personality and some experiences of performance.