  Different ways of the determination of masses of galactic disks, based on the
kinematic data, are briefly discussed. The analysis of the rotation curves
which reach maximum inside of a disk, and N-body modeling, reproducing the
rotation curves and stellar velocity dispersion of real galaxies, enable to
conclude that the mass of a disk is usually significantly less than the total
mass of spherical components (bulge + dark halo) inside of optical borders of a
galaxy, although the exceptions also exist.
