  We explore the noncommutative effect on single field inflation and compare
with WMAP five-year data. First, we calculate the noncommutative effect from
the potential and dynamical terms, and construct the general form of modified
power spectrum. Second, we consider the leading order modification of
slow-roll, DBI and K-inflation and unite the modification, which means the
modification is nearly model independent at this level. Finally, comparing with
the WMAP5 data, we find that the modified can be well realized as the origin of
the relative large spectral index and the quite small running.
