  In cavities, there exists not only the fundamental mode which is used to
accelerate the beam but also higher order modes (HOMs). The higher order modes
excited by beam can seriously affect beam quality, especially for the higher
R/Q modes. This paper reports on measured results of higher order modes in the
IHEP02 1.3GHz low-loss 9-cell superconducting cavity. Using different methods,
Qe of the dangerous modes passbands have been got. The results are compared
with TESLA cavity results. R/Q of the first three passbands have also been got
by simulation and compared with the results of TESLA cavity.
