  We have investigated properties of the Quasi Periodic Oscillation (QPO)
features in the accretion powered X-ray pulsar Cen X-3 over a period of about
four years using observations carried out with the Proportional Counter Array
(PCA) of the {\it {Rossi X-ray Timing Explorer}}. The observations cover a wide
range of X-ray intensity of the source in excess of the binary intensity
modulation. We have detected QPOs in 11 out of a total 81 pointings with the
PCA with rms intensity fluctuation upto 10%. The QPO peak frequency shows
clustering around 40 and 90 mHz with the QPO frequency having no dependence on
X-ray intensity. This indicates that either (a) the observed X-ray luminosity
of the source is not related to the mass accretion rate or inner radius of the
accretion disk or (b) that the QPO generation mechanism in Cen X-3 is different
from the beat frequency model or Keplerian frequency model that is believed to
be operational in most other transient and persistent X-ray pulsars. We have
also found that, the rms variation in the 40 mHz QPO feature is not dependent
on the X-ray energy, indicating that disk absorption related origin for the QPO
is unlikely.
