BEIJING, Sept. 11 -- China on Thursday released archives of an important battle against the Japanese army in 1939 which engaged more than 100,000 Japanese soldiers and 240,000 Chinese.

This is the 18th part of the series released daily by the State Archives Administration from Aug. 25, as the country marks the 69th anniversary of victory against Japan's aggression.

On Sept. 14 1939, a Japanese troop of more than 100,000 launched an offensive in Changsha in central China's Hunan Province.

The Chinese side assembled a troop of about 240,000 and held the defense line for about a month until the Japanese army retreated to their original base in mid-October.

The Changsha Battle, important in the zone mainly held by the Kuomintang army, exposed the Japanese army's weakness in large-scale offensives and greatly raised the morale of the Chinese army and people.

China has officially set Sept. 3 as Victory Day to mark Japan's surrender on Sept. 2, 1945.