Weak gravitational lensing of galaxy cluster provides a direct method
to probe their mass distribution. We report our preliminary results on the
analysis of a complete sample of $\sim 50$ massive galaxy clusters,
in the redshift range 0.1 - 0.6, in the Canada France Hawaii Telescope Legacy Survey (CFHT-LS), drawn from the large sample built by Covone et al. (2014). For each galaxy cluster, we determined the mass distribution from the radial shear profile, the mass-to-light ratio and the optical richness,in order to study how the galaxy population in clusters
trace mass as a function of scale. We have studied the scaling relation of mass with optical luminosity and richness for massive clusters. Moreover, by assuming that the average mass-to-light of galaxy clusters is very close to the cosmological values, we can determined the mass density of the universe.
Keywords: weak gravitational lensing : galaxy cluster