The problem of finding folding nuclei (a set of native contacts that play an important role in folding) along with identifying folding pathways (a time-ordered sequence of folding events) of proteins is one of the most important problems in protein chemistry. Here we propose a novel and simple approach to address this problem as follows: given the topology of the native state, identify native contacts that form folding nuclei based on a graph-theoretical approach that considers effective contact order (effective loop closure) as its objective function.