Abstract: Over the next decade, large scale structure (LSS) surveys will play an increasingly important role in the measurement of cosmological parameters and as a probe of initial conditions.  Relating the observed distribution of galaxies to the physics of the early universe requires a good understanding of several late-time sources of non-linear effects. Recently the effective field theory (EFT) principles have provided a new framework in which this evolution can be studied . In this talk, I will explain how, on large scales, effective field theory (EFT) offers a natural framework in which these short-scale non-linear effects can be systematically parametrized. After reviewing the recently developed effective field theory of large scale structure,  I will explain how the halo model - a model relating the density of dark matter halo to the underlying dark matter density - can also be understood in the context of EFT. I will show explicitly how the renormalization of halo correlation function is performed and discuss their observational consequences.