Objective　To explore the relationship between muscle tension and recovery of function during muscle transfer，and attempt to demonstrate that the sarcomere length is also a reliable indicator of muscle tension, which can be used to optimize muscle function.　Methods　10 male SD rabbits were used. The flexor digitorum longus muscle was cut distally and transferred and woven into the tibialis anterior tendon. Resting and transferred muscle length, sarcomere lengths were measured during the operation. Both flexor digitorum longus muscles of 10 rabbits were harvested and muscle contractive capacity and muscle wet weight maintenance rate, architectural analysis were detected in comparison the group under normal condition without changing length and tension 3 months after operation. The micro pattern was observed by comparison.  Result　With the increase of the intraoperative sarcomere length and muscle length relative ratio, the value of muscle contractive capacity and muscle wet weight maintenance rate after 3 months increases in the early stages and then decreased; Sarcomere length increasesas along with muscle length relative ratio; the relationship between them demonstrated a linear correlation as shown by linear regression analysis.  Conclusion　Following a long-term recovery period, a muscle set with increased tension contracts with better recovery of muscle function and negligible adverse effects to muscle fibers; Muscles produce maximum tensions at just over resting length, at about 104%~105% of resting length. The sarcomere length can be used as a characterization of muscle tension and proved to be an excellent predictor of active muscle force generated.