This table contains the results from a study of the X-ray to optical properties of a sample of 545 X-ray selected Type 1 AGN, from the XMM-Newton Cosmic Evolution (XMM-COSMOS) survey, over a wide range of redshifts (0.04 < z < 4.25) and X-ray luminosities (40.6 <= log(L<sub>2-10keV</sub>) <= 45.3). About 60% of them are spectroscopically identified Type 1 AGN, while the others have a reliable photometric redshift and are classified as Type 1 AGN on the basis of their multi-band Spectral Energy Distributions (SEDs). In the reference, the authors discuss the relationship between UV and X-ray luminosity, as parametrized by the X-ray to optical-UX alpha<sub>ox</sub> spectral slope, and its dependence on redshift and luminosity. Herein optical and X-ray properties for 545 Type 1 AGN in XMM-COSMOS are presented. For each source, X-ray ID, spectroscopic redshift, photometric redshift, upper error on the photometric redshift, lower error on the photometric redshift, logarithm of the monochromatic luminosity at 2500 Angstroms, logarithm of the monochromatic luminosity at 2 keV, alpha<sub>ox</sub>, logarithm of the 2-10 keV luminosity, logarithm of the bolometric luminosity in solar units, bolometric correction, photometric classification, logarithm of the Eddington ratio, logarithm of the black hole mass in solar masses, and a flag for the 2-10 keV detection (flag = 1 [343 entries] means a detection in the 2-10 keV band, while flag = 0 is for 2-10 keV upper limits) are given. This table was created by the HEASARC in May 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/512/A34">CDS catalog J/A+A/512/A34</a> file table2.dat. This is a service provided by NASA HEASARC .