  We report the recent charged Higgs search in top quark decays in 2.2/fb CDF
data. This is the first attempt to search for charged Higgs using fully
reconstructed mass assuming H->c-sbar in small tan beta region. No evidence of
a charged Higgs is observed in the CDF data, hence 95% upper limits are placed
at B(t->H+b) < 0.1-0.3. The upper limits can be used to limit the generic
non-SM charged boson production in top quark decays.
