BEIJING, Sept. 5 (Xinhua) -- China on Friday released archives of a key battle in Shandong Province in 1938, as the country marks the 69th anniversary of the victory against Japanese aggressors.

This is the 12th part of the series released daily by the State Archives Administration beginning Aug. 25.

In March 1938, the Japanese army prepared an attack on vital military area Tai'erzhuang in Shandong, but encountered fierce resistance of the Chinese army, according to the archives.

While most of the parts of Tai'erzhuang had fallen, the Chinese army convened its forces to encircle and fight back the invaders beginning March 31.

On April 7, Chinese army finally won the battle after killing over 10,000 enemies. They also captured about 11,000 rifles and machine guns, dozens of cannons and vehicles.

The battle marked one of the first important victories since the anti-Japanese war began on July 7, 1937 and was a heavy blow for the Japanese aggressors. It greatly boosted the morale of Chinese troops, according to the synopsis.

China has officially set Sept. 3 as the "Victory Day," 69 years after Japan formally surrendered.