The two opened the fair on the second day of Hu's visit to Russia.
Nearly 200 Chinese companies are showcasing their products at the fair, said to be China's biggest ever in a foreign country.
Hu's visit is aimed at cementing growing economic and political ties between the two countries.
After talks on March 26, the two presidents pledged to further develop energy cooperation. They also reiterated their aligned positions on Iran and North Korea's nuclear programs.
In talks with Prime Minister Mikhail Fradkov earlier today, Hu proposed more frequent meetings to pave the way for increased trade.
The Chinese president is also scheduled to travel to Russia oil-rich republic of Tatarstan today.
(compiled from agency reports)
Russia And Global Energy Security
An oil field in Russia's Republic of Bashkortostan (TASS file photo)
ENERGY SECURITY is increasingly moving to the top of the EU's agenda in its dealings the outside world. A recent report identifies the European Union's main energy objectives as not just securing gas and oil deliveries from Russia, but also ensuring that it has reliable alternative sources, including in Central Asia. Nonetheless, EU officials say relations with Russia take center-stage in their thinking....(more)