  It has been suggested that the mass-to-light ($M/L$) ratio of gravitationally
clustering objects is scale-independent on scales beyond galaxy clusters, and
may also be independent of the mass of the objects. In this paper, we show that
the scale behavior of $M/L$ ratio is closely related to the scaling of cosmic
structures larger than clusters. The scale dependence of the $M/L$ ratio can be
determined by comparing the observed scaling of richness function (RF) of
multi-scale identified objects with the model-predicted scaling of mass
function (MF) of large scale structures. Using the multi-scale identified
clusters from IRAS 1.2 Jy galaxy survey, we have made comparisons of the
observed RF scaling of IRAS $r_{cl}$-clusters with the MF scalings given by
simulations of three popular models SCDM, LCDM and OCDM. We find that, the M/L
ratio basically is scale-independent from the Abell radius up to about 24
$h^{-1}$Mpc, while it seems to show a slight, but systematical, increase over
this scale range. This result is weakly dependent on the cosmological
parameters.
