  The critical temperature and condensate fraction of a trapped interacting
Bose gas are investigated when both atom-atom interaction and finite-size
effects are taken into account. Canonical ensemble is used to obtain the
equations on the condensate fraction for the trapped interacting Bose gas near
and below the critical temperature. In our approaches corrections due to
atom-atom interaction and finite-size effects are obtained simultaneously for
the critical temperature and condensate fraction of the system. Analytical
high-order correction to the condensate fraction is given in this work.
