  Using a realistic equation of state (EOS) of strange quark matter, namely,
the modified bag model, and considering the constraints to the parameters of
EOS by the observational mass limit of neutron stars, we study the r-mode
instability window of strange stars, and find the same result as the brief
study of Haskell, Degenaar and Ho in 2012 that these instability windows are
not consistent with the spin frequency and temperature observations of neutron
stars in LMXBs.
