PURPOSE: A composition containing a collagen triple helix repeat containing 1 inhibitor is provided to suppress cancer metastasis, and a screening method is provided to efficiently identify a drug for suppressing the cancer metastasis. CONSTITUTION: A pharmaceutical composition for suppressing cancer metastasis comprises a gene expression inhibitor of collagen triple helix repeat containing 1(CTHRC1) or a protein expression inhibitor as active ingredients. A screening method for suppressing the cancer metastasis comprises the following steps. CTHRC1 is inserted to cancer cells. The level of the expression of phosphorylated extracellular signal-regulated kinases in the cancer cells is measured. The level of the expression of phosphorylated extracellular signal-regulated kinases is measured after treating the cancer cells with the candidate for suppressing the cancer metastasis. If the level of the expression after treating the cancer cells with the candidate is lower than the level of the expression without the treatment with the candidate, then the candidate is selected for an inhibitor for the cancer metastasis.본 발명은 CTHRC1 억제제를 유효성분으로 포함하는 암전이 억제용 약학적 조성물 및 암전이 억제제를 스크리닝하는 방법에 관한 것이다. 본 발명의 조성물은 암전이를 억제하기 위하여 유용하게 사용될 수 있다. 또한, 본 발명의 스크리닝 방법에 의하면, 효율적으로 암전이 억제용 치료제를 동정할 수 있다.