The Chiari malformation is one of the disorders of craniocerebral organogenesis and it's problem is hindbrain dysgenesis. The association between Chiari malformation and syringomyelia is well appreciated. In recent years, it has been observed that an abnormal dilatation of the central canal may also accompany anomalies of the neuraxis itself at the cervicomedullary junction. But Chiari malformation and syringomyelia have not previously been reported in a patient with ossification of posterior longitudinal ligament (OPLL), especially in young patient. We experienced one case which was provent to have the Chiari type I malformation with syringomyelia and OPLL and report the case with clinical, radiologic & electrodiagnostic findings.