; Zhang Shuang-Nan] Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China
; [Liang Nan
; Zhang Shuang-Nan] Tsinghua Univ, Tsinghua Ctr Astrophys, Beijing 100084, Peoples R China
; [Gao Chang-Jun] Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
; [Zhang Shuang-Nan] Chinese Acad Sci, Key Lab Particle Astrophys, Inst High Energy Phys, Beijing 100049, Peoples R China
We investigate the cosmological evolution of a two-field model of dark energy, where one is a dilaton field with canonical kinetic energy and the other is a phantom field with a negative kinetic energy term. Phase-plane analysis shows that the "phantom"-dominated scaling solution is the stable late-time attractor of this type of model. We find that during the evolution of the universe, the equation of state w changes from w > -1 to w < -1, which is consistent with recent observations.