  In a recent Letter, Jiang, Sun, Xie and Wang [Phys. Rev. Lett. 93, 076802
(2004), cond-mat/0408261] study transport through an interacting quantum dot
embedded in one arm of an Aharonov-Bohm interferometer. Based on a theoretical
analysis of the Aharonov-Bohm oscillation amplitude, Jiang {\it et al.} claim,
contrary to earlier work by two of us, that at finite temperature the intradot
interaction will {\em not} lead to any dephasing. Likewise, they claim that the
theoretically predicted and experimentally verified asymmetry of the
Aharonov-Bohm oscillation amplitude is {\em not} associated with dephasing. In
this Comment, we point out severe inconsistencies in the analysis of the Letter
by Jian {\it et al.}, and show that their conclusions are ill-founded.
