Muscle rupture is not a common disease. But it is known that partial muscle rupture commonly occurs to active sports athletes or heavy workers who receive severe physical stress. Gastrocnemius muscle rupture(this is called ‘tennis leg’)is often caused by sudden overstretching of the muscle through concomitant ankle dorsiflexion and knee extension. This rupture may result in a swelling and pain that is easily confused with other diseases like thrombophlebitis. Ultrasonography can confirm the clinical suspicion of tennis leg and the assessment of the size of the lesion, and can discriminate from other diseases. So it is a useful, noninvasive, low-cost modality to diagnose and follow up tennis leg. We experienced 2 cases of partial gastrocnemius muscle rupture patients who were treated by conservative methods or acupuncture therapy and followed up with Ultrasonography, and arrived at some interesting results, which we report along with a review of some relevant literature.