"Tim and I share a philosophy," the president-elect said during a news conference. "It's a pragmatic, progressive philosophy ... that measures the strength of an idea not by whether it's Republican or Democrat, but whether it can actually solve a problem and make a difference in people's lives."
Obama praised outgoing Democratic National Committee Chairman Howard Dean for his "outstanding work" in putting the party in a strong position.
"For nearly four years, Howard has served our party and our nation as a visionary and effective leader," Obama said. "He launched a 50-state strategy that made Democrats competitive in places they had not been in years ... to give Democrats a majority in the House for the first time in over a decade."
Kaine pledged to do three things as DNC chair.
"I want to promote this president's agenda. I want to carry the proud banner of a proud party," he said. "And I want to work to creatively engage citizens in new ways through this party to be active in civic life."