Abstract: The English song "You Are My Sunshine", written by Jimmie Davis and Charles Mitchell and sung by Jimmie Davis on February 4th, 1940, was so popular that it became King George VI's favourite. Why was it so successful? So far, despite a few linguistic studies on songs, no research on this song is available. This paper analyzes the text of this song from the perspective of experiential function and finds that different from the findings of the existing literature that material processes are dominating in songs, the major types of process in this song text are mental and relational processes, and that all processes involve typical verbs indicating love related to physical and mental behaviour and to "you-me" relationship so that the text gives its listeners the unforgettable impression of closeness, which is linguistically part of the key to its great success. In addition, the conclusion and weaknesses of the analysis are also briefly discussed.