Abstract: the relation between cohomology operations and simplicial cochain operations was initialized by L. Kristensen [Kri67]. He worked with acyclic models and inductive computations making use of the explicit structure of the cohomology of Eilenberg-Mc Lane spaces known by the results of Serre and Cartan. An alternative of this method is to obtain this relation using algebraic filtrations with a cartesian products of n copies of a simplicial set X as the base space and a subgroup of the symmetric group S_n as the fiber space. This last point of view closely follows the original work of Steenrod squares aboyut cohomology operations [SE62]. With this method and a process of simplification we are able to obtain explicit combinatorial formulation (in terms of face operations of X) of cohomology operations at cocycle level. Passing to cohomology can be done using homotopy equivalences between the cochain complex and the cohomology of X.