The Chinese People's Liberation Army (PLA) started its largest-ever military exercise on Tuesday. Experts said the exercise has already revealed new trends in the country's military development.

It is the first time the PLA has mobilized four full divisions amounting to about 50,000 troops and deployed 60,000 pieces of heavy equipment up to a maximum of 2,400 kilometers from their bases, accompanied by army aviation units.

A foot soldier takes part in a joint training exercise on Tuesday. The exercise "Stride-2009" participated by one army division from each of the military commands of Shenyang, Lanzhou, Jinan and Guangzhou begins. [Xinhua]

To test the mobility of the world's biggest army, numbering nearly 2.3 million - which has not been engaged in a major military conflict for nearly 30 years - PLA headquarters selected four elite divisions from its Lanzhou, Shenyang, Jinan and Guangzhou Military Commands to carry out the two-month long exercise.

The PLA's General Staff Headquarters said three of the divisions had glorious battle histories stemming from victories in the Sino-Japanese War (1937-1945) and victories against US troops during the Korean War (1950-1953).

"They are required to improve PLA battle effectiveness in a modern warfare environment for the present and in the future," Gong Fangbin, a professor at the PLA's National Defense University, said Wednesday.

"Long-distance mobility is a key requirement for the armed forces to carry out anti-terror missions and operations to protect China's overseas interests," Gong said.

Motorized troops from the military commands of Lanzhou passes a bridge on Tuesday. The exercise "Stride-2009" participated by one army division from each of the military commands of Shenyang, Lanzhou, Jinan and Guangzhou begins. [Xinhua]

The professor said the exercise also revealed a transformation of the country's defense construction concept.

"China is less likely to face a large scale inland attack since no other countries -- including the United States -- want to take the chance of adopting military force in dealing with Chinese affairs.

"Instead, China is now in growing demand of smaller, agile task forces able to conduct precise joint operations," he said.

According to PLA Headquarters the exercise, code named Stride-2009, includes coordination between army ground troops and aviation units.

"There are comparative weaknesses the PLA should overcome before it has real ability to conduct joint operations," Gong said.

According to a report by the PLA Daily on Wednesday, the army's Jinan Military Command held joint training in July which involved the army, navy and air force as well as the second artillery force and militia in the east Shandong peninsula and central Henan Province.

It was the first PLA theater-level joint training in which all of the army's services within one of its major military regions participated.