Abstract The statistical properties of dark matter distribution in the Universe are crucially dependent on the parameters used to describe cosmology. The distribution of galaxies in the Universe traces the distribution of dark matter. Therefore, observations of galaxies can provide important information about the cosmological parameters. However, this requires an accurate knowledge of how the galaxy distribution is biased with respect to the dark matter distribution. We have developed a unique statistical tool, the conditional luminosity function (CLF) which can be used to specify how galaxies occupy dark matter halos and consequently specify the galaxy bias. The CLF can be used to predict various observables properties of the galaxy distribution. I shall focus on the abundance of galaxies, their clustering strength and the galaxy-galaxy lensing signal around them and present constraints on cosmological parameters obtained from a combination of these observables.