Abstract: The empirical evidence of flexibility is systematically summarized from the perspective of physical health, and the evaluation significance and physical exercise value are reexamined in the aspects of health benefit and exercise types, trying to provide references for the revision of index system for physical fitness surveillance as well as the optimization of exercise prescription (planning). It is believed that flexibility lacks definite effects on all-cause mortality, fall risk, cardiovascular risk, and activities of daily living. There may be a U-shaped relationship between flexibility and sports injury risks, and the effects of static stretching exercises can be almost displaced by resistance exercises. The suggestions are as follows: The importance of flexibility in physical fitness should not be exaggerated nor emphasized, the test value and evaluation criteria of sit-and-reach on each age group should be reviewed in the physical fitness surveillance. In the instruction and practice of exercise, static stretching exercises can be reduced according to the actual situation of the exercisers thus to improve the efficiency of physical exercise.