Wound healing and function recovery of injured tendons are still a big challenge for orthopaedic surgery. Evidence in clinic shows that early controlled motion has significant favourable effects on tendon healing; however, the mechanisms involved in are not fully understood. In the present study, it was shown that an appropriate mechanical stretch (10% strain, 0.5 Hz for 1 h) evidently promotes rat tenocyte migration and nuclear morphology changes. The farther research discovered that mechanical stretch had no effect on Lamin A/C expression, but it could promote chromatin decondensation. Moreover, the histone modification plays an important role in mechanical stretch‐mediated chromatin decondensation. Inhibition histone modification could inhibit mechanical stretch‐promoted nuclear morphology changes and tenocyte migration. These results indicating that mechanical stretch may promote tenocyte migration via chromatin remodelling‐mediated nuclear morphology changes, which contribute to a better understanding of the role of mechanical stretch on tenocyte migration and repair of injured tendon. [ABSTRACT FROM AUTHOR]