Abstract: Recent claims suggest foam roller is useful in self-myofascial release and is a stretching technique used by health care professionals to treat patients with a variety of soft tissue conditions including muscle tightness.Objective:To explore the utility of foam rollers to Increase the flexibility of the hamstring muscle group in order to give suggestions for sports prescription of athletic or rehabilitative training design.Methods:28 male college students whose knee extension range of motion less than 80°participated in this study.The subjects were randomly divided into 4groups (1control group and 3treatment groups) for three days a week, throughout eight weeks the foam rolling intervention, every time duration control groups was 0min, 3treatment groups were 3, 6, 9 minutes, and continue to track measuring 4 weeks when the 8weeks experiment finished.The measurement for testing was knee extension range of motion.Every week each subject answered the subjective flexible questionnaire.Resultsand Conclusion:The knee extension range of motion was increased following the foam rolling time prolonged, however the amplitudes were diminished;the knee extension range of motion of dominant leg were increased following the foam rolling periods;when 8weeks foam rolling finished and stopped, the knee extension range of motion was decreased following the foam rolling periods, the amplitudes were increase.Foam roller possible increased the flexibility.But use the foam rolling to improve flexibility maybe is not a long-term technology, it is suggested to combine other stretching protocols to improve flexibility.