  From the damping of the Cosmic Microwave Background Radiation
  (CMB) anisotropy power spectrum at large scale and the recent accelerating
expansion of the Universe, we find that, there may be a largest scale which we
can detect in the Universe. From this, we can get the inflation parameters as
spectrum index $n_s$, e-fold
  $N$, Hubble parameter $H$, the ratio of tensor and scalar $r$, the lasting
time of reheating time $\alpha$ for special inflation models. We do them in
three inflation models, and find that all the results fit very well with the
observations and the inflation theory.
