  The goal of this paper is to approximate several kinds of {\it Mckean-Vlasov
SDEs} with {\it irregular coefficients} via weakly interacting particle
systems. More precisely, propagation of chaos and convergence rate of
Euler-Maruyama scheme associated with the consequent weakly interacting
particle systems are investigated for Mckean-Vlasov SDEs, where (i) the
diffusion terms are H\"older continuous by taking advantage of
Yamada-Watanabe's approximation approach and (ii) the drifts are H\"older
continuous by freezing distributions followed by invoking Zvonkin's
transformation trick.
