In this paper, we investigate a two-species competitive chemotaxis Keller-Segel system equipped with a free boundary. The local existence and global existence of classical solutions are established, and then the asymptotic behavior of the solutions is described. Some spreading-vanishing dichotomies have been obtained both for the strong competition case: 0 < a(1) < 1 <= a(2), and weak competition case: 0 < a(1), a(2) < 1. Finally, an obstructed spreading case has been found, which could happen due to the effect of the chemotaxis. (C) 2021 Elsevier Inc. All rights reserved.