Purpose: This study was designed to determine the quantitative changes of the numbers of the mechanoreceptors in the experimentally tenotomized Achilles tendon of rabbits as compared with short-term immobilization and long-term immobilization. Materials and Methods: 14 white rabbits were used. After tenotomizing the right Achilles tendon, the subjects were divided into 2 groups according to the periods of immobilizaton. The left side of each Achilles tendon of the rabbits were used as controls. The tendons were stained with a modified gold-chloride method. Results: The number of mechanoreceptor was significantly decreased in the tenotomized Achilles tendon group than the control group (p<0.01). There was no statistical difference between the two experimental groups in the numbers of the mechanoreceptors (p>0.01). Conclusion: The injured Achilles tendons may more vulnerable to injury because of the decreased numbers of mechanoreceptors, but no difference between the periods of immobilization. It may suggest that post-operative immobilization period may not affect on the outcome of operative treatment from the viewpoint of mechanoreceptors.