Hu, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission (CMC), flew to the quake-hit area to console the victims and inspect the rescue and relief work.
Hu will also visit the troops and medical workers who are engaged in around-the-clock relief efforts in the quake areas.
As of 4 p.m. Thursday, the confirmed death toll in Sichuan alone was 19,509 and more than 50,000 people were feared dead.
Also Friday morning, Premier Wen Jiabao told Chinese media on a train in Sichuan that saving lives remained the top priority almost four days after the quake.
"We won't give up if there is even the slightest hope of finding more survivors," he said.
Wen said the quake was "the biggest and most destructive since new China was founded in 1949," and the quick response had helped reduce casualties to the greatest extent.
The premier vowed "to pour out whatever the country is capable of" to combat the massive disaster and fight till the end.
To move forward with relief work, the country needs confidence, resolution, perseverance and forceful organization work, he said.
"We believe that so long as we rely on the people, the military and the civilians unite together, the officials and the general public unite together, and together we stand, we will surely win this anti-quake battle," Wen stressed.