  This work studies the optical emission line properties of a sample of 155
low-redshift bright X-ray selected ROSAT Seyfert~1 type AGN for which adequate
signal-to-noise ratio spectroscopic observations are available. We measured
emission line properties by performing multi-component fits to the emission
line profiles, covering the effect of blended iron emission. We also obtained
continuum parameters, including 250eV X-ray luminosities derived from the ROSAT
database. In addition, the measured properties are gathered for a correlation
analysis, which confirms the well-known relations between the strengths of
Fe~II, [O III] emission and the X-ray slope. We also detect striking
correlations between H$\beta$ redshift (or blueshift), flux ratios of Fe `II to
H$\beta$ broad component and [O III] to H$\beta$ narrow component. These trends
are most likely driven by the Eddington ratio.
