In order to Screening antitumor drugs tartgeted to IGF1R gene, 9 different 20-mer anti-sensitive oligo-deoxyribonucleic acid (ASODN) were designed according to the mRNA second structure of IGF1R gene and were transfected into tumor cells under various conditions in the presence of lipofectin. Cell growth activity were evaluated by MTT assay. The best sequence with antitumor activity in vitro and in vivo were analyzed. This sequence showed strong anticancer activity in vitro and in vivo and had dose -dependent relation. The sequence had no obvious toxicity on tumor -burdended nude either . IGF1R could be used as an appropriate target for tumor therapay.