"I think United Russia has made a correct decision to allocate 20% of its voting lists to young people," Putin said at a meeting with United Russia faction in his country residence, Lesnye Dali, outside Moscow.
Putin said only six out of 310 members in the lower house of parliament were under 30 when elected.
"This proportion does not correspond to the age structure of society or reflect how important youth problems are in reality," the president said.
He said that young people should be given the opportunity to defend their interests in politics.
"Otherwise, the energy of their age will be wasted on running around to collect signatures or put up leaflets," the president said.
Putin also said that distribution of gender- or age-based quotas remained disputable, but added that other parties practiced such an approach. He urged United Russia to give consideration to the idea.
