  Mechanisms regulating the evolution of pre-main sequence stars can be
understood by studying stellar properties such as rotation, disk accretion,
internal mixing and binarity. To investigate such properties, we studied a
sample of 332 candidate members of the massive and populous star forming region
NGC 6530. We want to select cluster members by using different membership
criteria,to study the properties of pre-main sequence stars with or without
circumstellar disks. We use intermediate resolution spectra including the Li I
6707.8 Angstroms line to derive radial and rotational velocities, binarity and
to measure the Equivalent Width of the lithium line; these results are combined
with X-ray data to study the cluster membership. Optical-IR data and Halpha
spectra, these latter available for a subsample of our targets, are used to
classify CTTS and WTTS and to compare the properties of stars with and without
disks. We find a total of 237 certain members including 53 binaries. The
rotational velocity distributions of stars with IR excesses are statistically
different from that of stars without IR excesses, while the fraction of
binaries with disks is significantly smaller than that of single stars. Stars
with evidence for accretion show circumstellar disks; youth of cluster members
is confirmed by the lithium abundance consistent with the initial content. As
indicated by the disk-locking picture, stars with disks have in general
rotational velocities lower than stars without disks. Binaries in NGC 6530 seem
have undergone a significant disk evolution.
