Di(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizer in polyvinyl chloride (PVC) products. Mono(2-ethylhexyl) phthalate (MEHP) is initial metabolism of DEHP in animals and humans, which is harmful to animals and humans. The method for determining MEHP was established using GC/MS in this paper. The yield of MEHP in litchi wine was detected using this method.