  We study the infrared (K_s band) properties of clusters of galaxies in the
Ursa Major supercluster using data from 2MASS (Two-Micron All-Sky Survey) and
SDSS (Sloan Digital Sky Survey). We identified three large filaments with mean
redshifts of z = 0.051, 0.060, and 0.071. All clusters of the supercluster are
located in these filaments. We determined the total K_s-band luminosities and
masses for 11 clusters of galaxies within comparable physical regions (within a
radius R_200 close to the virial radius) using a homogeneous method. We
constructed a combined luminosity function for the supercluster in this region,
which can be described by the Schechter function with the following parameters:
M*_K = -24^m.50 and \alpha = -0.98. The infrared luminosities of the clusters
of galaxies correlate with their masses; the M/L_K ratios of the systems
increase with their masses (luminosities), with most of the Ursa Major clusters
of galaxies (particularly the richer ones) closely following the relations
derived previously for a large sample of clusters and groups of galaxies. The
total mass-to-infrared-luminosity ratio is 52 M_{\odot}/L_{\odot} for six Abell
clusters and 49 M_{\odot}/L_{\odot} for all of the clusters, except Anon2.
