This study compared and measured the flexibility and retention period of PNF(Proprioceptive Neuromuscular Facilitation), Bouncing, and NDM(Neuro Dynamic Mobilization) so that it proved the excellence of each stretching technique. Fifteen subjects with the dearth of hamstring flexibility participated in this study. The subjects divided into three groups. Each group was apported 5 subjects(2 men, 3 women). The result of four-week-exercise suggested that the flexibility of hamstring has been enhanced after applying those stretching techniques. According to the study, Bouncing topped the list when it came to the flexibility, followed by PNF and NDM. However, there was difference on Retention period; the result showed that the flexibility of hamstring applied PNF maintained remarkably but the flexibility of hamstring was not significant as time went by. The study proved that Bouncing was effective to improve the flexibility for a while, wheres PNF had an effect on retention period of flexibility.