A method for fractionating soluble fractions of peas, includes, in sequence, a step of microfiltering or centrifuging, followed by a step of ultrafiltering, and optionally a reverse-osmosis step. A reduction of the leakage of proteins toward the soluble fractions, an improvement of the yield of the single concentration step by evaporating the soluble fractions, and the selective isolation of proteins of interest are thus achieved. The method is easy to implement, the devices used at each single step are conventional and well known to the person skilled in the art. Also, the method does not use any organic solvent other than water.