Literatures and operas in late nineteenth century were mainly based on Realism which focused primarily on pressing close to the general public and depicting the real and truthful sides of characters. Hence, it was necessary for composers to apply melody, harmony, and lyrics to sculp personalities and emotions for their characters. And Giacomo Puccini （1858-1924）is regarded as one of the most important composers for Realistic Operas.

In this paper, the author began with research in Bel Canto which rose from Realism, and further addressed its characteristics for understanding the difference in singing methods of Bel Canto in Realistic Operas versus the traditional methods in the past. Meanwhile, Puccini’s compositional style and characteristics were comprehended through his life and backgrounds. Finally, stories of 《Manon Lescaut》 and 《La Bohème》, Puccini’s two important operas, were introduced. And four arias sung by leading actresses of these two operas, i.e., Manon’s “ Sola, perduta, abbandonata” and “In quelle trine morbide”, as well as Mimi’s “ Si, mi chiamano Mimì”, and “ Donde lieta uscì” were also included. They were used to analyze the melody, harmony, tonality and the connection between lyrics and melody in order to verify musical characteristics of Realism with Puccini's compositional techniques. Interpretation highlights and recommendation for singing of these arias were also presented by the author.