This paper attempts to analyze Memory, a episode in the music theater Cats, from the perspective of functional stylistics. Episodes play crucial role in the development of the entire storyline. Therefore, the paper discusses the conceptual function and interpersonal function respectively on the basis of functional grammar, aiming to deeply understand the connotation of the song and reveal the whole life of the charming cat. It also expected to provide a new perspective for the analysis of musical lyrics, and test the practicality and maneuverability of functional grammar in lyrics analysis.