  It is well known that the [O {\sc iii}]$\lambda$5007 emission line and hard
X-ray(2-10keV) luminosities are good indicators of AGN activities and that the
near and mid-infrared emission of AGN originates from re-radiation of dusty
clouds heated by the UV/optical radiation from the accretion disk. In this
paper we present a study of the near-infrared K-band (2.2$\mu$m) properties for
a sample of 65 Seyfert 2 galaxies. By using the AGN/Bulge/Disk decomposition
technique, we analyzed the 2MASS K$_{\rm S}$-band images for Seyfert 2 galaxies
in order to derive the K$_{\rm S}$- band magnitudes for the central engine,
bulge, and disk components. We find that the K$_{\rm S}$-band magnitudes of the
central AGN component in Seyfert 2 galaxies are tightly correlated with the [O
{\sc iii}]$\lambda$5007 and the hard X-ray luminosities, which suggests that
the AGN K-band emission is also an excellent indicator of the nuclear
activities at least for Seyfert 2 galaxies. We also confirm the good relation
between the central black hole masses and bulge's K-band magnitudes for Seyfert
2s.
