He is expected to meet with Mintimer Shaimiev, the president of Tatarstan, a mainly Muslim province in central Russia with large oil reserves.
Hu has already secured increased oil shipments from Russia during the three-day trip. He and Russian President Vladimir Putin earlier signed $4 billion worth of trade deals.
Chinese media are reporting today that China and Russia will mount a joint effort to explore Mars and one of its moons in 2009. Putin and Hu signed an agreement on the project on March 26.
Under the plan, a Russian rocket will lift a Chinese satellite and Russian exploration vehicle to survey Mars and Phobos, the innermost and biggest of the red planet's moons.