We report a case of lateral semicircular canal cupulolithiasis in a 12 years old child.He presented to ENT clinic due to vertigo and nausea for 4 hours.Roll test showed strong apogeotropic nystagmus for about 70 seconds when roll to the left recumbent position.The right lateral semicircular canal cupulolithiasis was diagnosed.The child was treated with the Li's quick repositioning maneuver and the vertigo was disappeared.His symptoms did not occurred after 6 months follow-up.