Abstract: With the study of the problem of the man’s subjectivity and value going deeper,and closer attention being paid to the modern human dilemmas,the problem of rationalneed and rationality of practice comes out the forestage.Man’s nature and need and practice have inherent consistency.Therefore,the rationality of need is the precondition and crucial tache to the rationality of practice.The rationalization of need and practice is inward meaning of man’s  all-round development,and also is the outlet of conquering modern human dilemmas and realizing man’s all-round free development.

Key words: need, practice, rationality