Lili Boulanger (1893-1918) is the first female composer to win the Prix de Rome in France. She had an early death due to Crohn¡¦s Disease at the age of twenty-four. During her brief and difficult life, she completed more than thirty musical pieces, one third of which were choral works. The 1913 Prix de Rome award is a clear line of demarcation of Lili's choral compositions. The early secular choral works, composed for the preparation of the first round of Prix de Rome(1911 to 1913), are much less known; her four well-known grand sacred choral works¡Ð¡§Psaume 24¡¨, ¡§Psaume 129¡¨, ¡§Psaume 130¡¨ and ¡§Vieille prière bouddhique¡¨¡Ðwere written between 1913 and 1918. Regrettably, the early secular works have been overwhelmed by the four splendor sacred works in the past century. Nine of the early works survive, and they were: ¡§Sous bois¡¨, ¡§Renouveau¡¨, ¡§Les sirènes¡¨, ¡§Soleils de septembre¡¨, ¡§Pentant la tempête¡¨, ¡§La source¡¨, ¡§Hymne au soleil¡¨, ¡§Pour les funérailles d¡¦un soldat¡¨ and ¡§Soir sur la plaine¡¨. The lyrics are from nineteen-century French poems; the music has such extreme intensity, dramatic power, demanding vocal techniques, as well as challenging piano skills. This thesis consists of five parts: an introduction, a basic review of Lili Boulanger¡¦s life and works, the analysis of the nine secular choral works, the interpretation of the works and a conclusion. There are also three appendices attached. Appendix 1 offers the translation and a pronunciation guide of the nine works. Appendix 2 is the program of the conducting recital. Appendix 3 is the program of the lecture recital.