Abstract: The Grass is Singing，written by Doris Lessing，a famous British writer，describes tragic fate of Mary Turner，a white woman，who is immersed in sychological dilemma． Based on the theory of Lacan's psychoanalysis，this paper tries to discuss the deep reason that causes Mary to go insane and finally die in tragedy: the ideal ego，constructed by the subject in the Imagine Order，produces sense of illusion which forces the subject to go through Alienation; in the Symbolic Order，the subject fails to identify with the law of the Father． Therefore，the subject，who loses the subjectivity，is in the state of being split and finally
goes insane．

Key words: Foreign literature , The Grass is Singing, Jacques Lacan, insanity, construction of the Ego