Provided is a fusion protein comprising circularly permuted form of TRAIL, and the fusion protein contains circularly permuted form of TRAIL and oligopeptides located at the N-terminus and/or C-terminus of the permuted form. The oligopeptides contain a repeating sequence consisting of 3-10 histidines. The components of the circularly permuted form of TRAIL from N-terminus to C-terminus are: (a) amino acids 135-281 of TRAIL, (b) a linker, and (c) amino acids 121-135 of TRAIL or amino acids 114-135 of TRAIL or amino acids 95-135 of TRAIL or any fragments of amino acids 95-135 of TRAIL containing amino acids 121-135 of TRAIL. Also provided is a method for treating cancer by using the fusion protein.
