We revisit the power spectrum analysis of the complete sample of the two degree field ( 2dF ) QSO redshift ( 2QZ ) survey , as a complementary test of the work by Outram et al .
( 2003 ) .
A power spectrum consistent with that of the 2QZ group is obtained .
Differently from their approach , fitting of the power spectrum is investigated incorporating the nonlinear effects , the geometric distortion and the light-cone effect .
It is shown that the QSO power spectrum is consistent with the \Lambda cold dark matter ( CDM ) model with the matter density parameter \Omega _ { m } = 0.2 \sim 0.5 .
Our constraint on the density parameter is rather weaker than that of the 2QZ group .
We also show that the constraint slightly depends on the equation of state parameter w of the dark energy .
The constraint on w 
from the QSO power spectrum is demonstrated , though it is not very tight .