  This proceedings contribution summarizes first results obtained from a
systematic study of 2011 NLS1 galaxies, as presented in Zhou et al. (2006, ApJS
166, 128). The sample was compiled by examining the spectral parameters of
galaxies and QSOs derived from SDSS DR3 data. We discuss some preliminary
results on the statistic properties of the sample, such as the fraction of
NLS1, the properties of broad and narrow emission lines, and emission in other
wavebands. The black hole mass--velocity dispersion relation for NLS1s was
re-examined using the velocity dispersion values estimated from the stellar
absorption spectra of the host galaxies. Preliminary result from an X-ray study
for a small subset using data obtained by XMM-Newton is briefly discussed.
