The present invention provides an oligodeoxy nucleotide for preparing drugs for inhibiting tumor growth and an application thereof. The core sequences of the oligodeoxy nucleotide is TTTCSCGCS, wherein S is C or G. The oligodeoxy nucleotide above further comprises an antisense strand and a modified type thereof. The oligodeoxy nucleotide according to the present invention plays a role of inhibiting the tumor growth in vitro and vivo, and is expected to be used for preparing drugs for inhibiting tumor growth, with high specificity and high inhibition ratio.
