13 patients with surgically treated congenital superior oblique palsy are presented. Follow-up ranged at least three months after surgery. Most patients received one operation, three cases required the secondary operation. Clinical symptom, Asymmetrical palsies: anomalous head posturing; hypertropia in primary position. Symmetrical palsies; a right hypertropia in left gaze and left hypertropia in right gaze; a positive Bielschowsky test on tiltion the head toward either shoulder, many cases have "V" pattern. The patients who need operation should usually undergo bilateral surgery. The most patients obtained satisfactory results after surgery.