Provided is a polypeptide having anti-tumor activity. The amino acid sequence of the polypeptide is FPGSDRF, X-FPGSDRF, FPGSDRF-Z, or X-FPGSDRF-Z, S being a phosphorylated serine residue, X and Z each being an amino acid residue or an amino acid sequence, X being selected from one of F, (R)9, (R)9-F, 6-aminocaproic acid, 6-aminocaproic acid-F, 6-aminocaproic acid-(R)9, and 6-aminocaproic acid-(R)9-F, and Z being selected from one of A, (G) n-RGD, and A-(G)n-RGD. The polypeptide has no toxicity for normal histocytes. However, when being used with chemicals (such as arsenic trioxide), the polypeptide can increase toxicity for tumor cells. Also provided are uses of the polypeptide for preparing anti-tumor drugs.
