The irreversibility lines of silver-sheathed (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 1 0 (Bi-2223), (Tl,Pb,Bi)(Sr,Ba) 2 Ca 2 Cu 3 O 9 (Tl-1223) and (Tl,Pb)Sr 2 Ca 3 Cu 4 O 1 1 (Tl-1234) superconducting tapes were investigated and compared with those of other superconducting systems. We have demonstrated that the shape of the irreversibility lines of Tl-1223 and Tl-1234 superconducting tapes are similar in behavior to those of YBa 2 Cu 3 O 7 (Y-123) and (Tl,Pb)Sr 2 (Ca,Y)Cu 2 O 7 (Tl-1212) systems and better than those of Tl 2 Ba 2 Ca 2 Cu 2 O 1 0 (Tl-2223) and (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 1 0 (Bi-2223) superconductors. This means that the flux pinning ability of Tl-1223 and Tl-1234 superconducting tapes was stronger than that of Bi-2223 and Tl-2223 superconductors. The possible reason for controlling flux pinning can be attributed to the intrinsic crystal structure difference in the materials.