Francis Poulenc (1899-1963) is considered one of the foremost French composers of the twentieth century due to his expressive melody and the genius of harmonic progression. As a member of “les sixs” in 1920-24, the music style of Poulenc can be inferred to the Neo-Classicism. "Quatre motets pour un temps de penitence", one of the most dramatic works, was completed during 1938-39. The motet plays a key role in Poulenc’s life, which symbolizes a mature composer.

This thesis is divided into four parts, respectively: Artistic development and musical style of Poulenc; Poulenc’s choral works; the analysis of "Quatre motets pour un temps de penitence"; and the performance practice of the motets.

The first chapter focuses on the development of Poulenc's musical style, which can be divided into four stages and each of them is studied amply. The second chapter concentrates on the features of secular and sacred works, and the background of the motets. The third chapter focuses on the analysis of the structure and the application of his composition devices such as texts, form, harmony, texture, and word- painting. The final chapter argues the performance practice, which deals with the issues such as tempos, dynamics, and qualities of voice.