Alveolar soft-part sarcoma(ASPS) is a rare, aggressive malignancy of uncertain histologic origin with a propensity for vascular invasion and distant metastasis. ASPS may mimic benign vascular neoplams of malformation but careful evaluation of the unique imaging features on CT scans, MR images, and angiograms lead to the correct diagnosis. ASPS of the tongue is slow-growing, painless mass, especially ASPS of the base the tongue is difficult to be noticed by patient, dentists or oral and maxillofacial surgeons on oral examintion because of its location and clinical resemblance to a benign lesion. And it leads to delayed or inadequate diagnosis. We report radiologic and clinical features of an ASPS of the basal portion of the tongue in a 17-year-old boy, showing normal appearance, but palpation of the tongue and floor of the mouth reveals the tumor. Among the 23 cases of a primary ASPS of tongue reported, 7 cases occured on the basal region of the tongue, inculding the present one. There has been no recurrence or metastasis as of 3 years postoperatively.