The research objects of this thesis are the two Piano Sonatas of L. v. Beethoven’s Op. 14-1 and Op. 14-2. These two Piano Sonatas are often neglected by researchers. Opinions towards these two Piano Sonatas can be divided into two opposing extremes: some scholars regarded them as excellent works, though others deemed it as clumsy ones. Furthermore, in Taiwan there are few theses fully analyzing and comparing the differences between these two Piano Sonatas. According to the induction and arrangement of the author of this thesis, there are actually some particular points of these two Piano Sonatas worthy of attention. In this thesis, the author would begin with the introduction of L. v. Beethoven’s life. Then, the author would state the three-period schema to divide Ludwig van Beethoven’s life into three periods. Finally, the form, the interpretation, and playing skills needed of Piano Sonatas: Op. 14-1 and Op. 14-2 would be analyzed. Especially, details of playing skills should be paid attention to would be discussed.