This thesis focuses on Beethoven’s “Piano Sonata No.31 in A flat Major, op.110”, which is composing during the last period of the composer’s life,

This thesis is composed of five chapters. Chapter 1 deals with the motivation and purpose of my research, and the method and scope I use in analyzing this work. Chapter 2 talks about brief biography and works during Beethoven’s later period. From the living environment and background of creation to the influence that Beethoven cause , probe into the forming and transition of the style of its later period. Chapter 3 put the discussion to the style and characteristic of every periods of Beethoven’s piano sonata. Beethoven's piano sonata has reflected the personality, background of life, composing style and the hidden feeling of all one's life. Chapter 4 is to study on Op.110. At first, do deep understanding to its background of creation, and then probe into the musical form and artistic technique of every movement one by one. Chapter 5 is to summarize the characteristic of my research findings in Op. 110. Through the analyses that we realize how Beethoven applied his mechanism on his works. Chapter 6, hope that I am more capable of interpreting performances more fully by researching on mechanism and style of aesthetics of Beethoven’s composition in later period.