We investigate inflation in closed Friedmann-Robertson-Walker universe filled with the scalar field with power-law potential .
For a wide range of powers and parameters of the potential we numerically calculate the slow-roll parameters and scalar spectral index at the epoch when present Hubble scale leaves the horizon and at the end of inflation .
Also we compare results of our numerical calculations with recent observation data .
This allows us to set a constraint on the power of the potential : \alpha \lesssim ( 3.5 \div 4.5 ) .