Provided is a drug for skipping the 51th exon of human dystrophin gene with high efficiency. The present invention also provides an antisense oligomen which is capable of skipping the 51th exon of human dystrophin gene.提供高效率跳讀人類肌肉萎縮蛋白基因第51號外顯子之藥劑。本發明係提供可跳讀人類肌肉萎縮蛋白基因第51號外顯子之反義低聚物。