Sunwu county locates in the north of Heilongjiang, to the north of Xiaoxinganling, facing Constantine Knoffca area of Atemuei state of Russia, The boundary line is 38 kilometers long. It is one of the three port cities of Heihe city. In 20 th century 30 `s , to attack the Soviet union, the Japanese built the fort in Sunwu county, stationed 100000 troops. Sunwu county became strategic place, so is named “big Sunwu, small Harbin”.

  In April ,1933, according to Guandong Project , the sketch of attacking Soviet union was formulated. The north defense plan was implemented then. The boundary between Sino-Soviet was divided into four parts: eastern frontage includes Mudanjiang and Jiandao provinces. Northeastern frontage includes Shanjiang province. Western frontage includes Xinganling province. Northern frontage named Sunwu county or Heihe frontage includes Sunwu county. The four parts were controlled by the north army of Japanese .

  In Nov, 1936, Japan and Germany signed the “resisting communist agreement” , whose aim is to attack the soviet union , thereafter, Japanese  stepped up the strategic preparation to attack the soviet union. They planned to send one division troop to gather in Heihe area to attack and attract and divert the military strength of the soviet union. Based on the Xiaoxinganling, the other troop gathered in Sunwu is to face  the protracted war , which has four divisions troops, independent machine gun brigade, two light armoured squadrons, one combat tank regiment, one field operation machine gun brigade , one heavy artillery regiment, one artillery intelligence class, eight field anti-aircraft fire artillery teams, as well as independent air unit, engineering soldier team.

  Sunwu fort construction began in 1933, which has two parts. Part one : the construction of the four frontage military parts. Part two : the headquarters construction which took Sunwu as the key point. The construction was divided into several stages.  At first , they build transportation : the Beihei railroad  and the other several roads, this make Sunwu the keypoint of north Heilongjiang. They began building the airplane in 1937. The massive military engineering covers 255 square kilometers mountainous regions and plain. Sunwu fort has four border positions, of which the Shenshan fort is well preserved , from which we can see something .

  Shengshan fort was called number fifth border position then.  The first line position was the ministers along the bank of the river where Japanese watch the Soviet soldiers with telescope. The second line position is Shengshan position , which has the commander, military camp and supply section. The fort has anti-tank trench, soldier trench , artillery fortification, machinegun blindage , the military camp locates underground which has hospital , kitchen, well, air vent, air disinfecting equipment. The underground equipment was made up of cement concrete that is so thick that they can resist the attack of tank and heavy artillery.

  The laborers that Japanese grasped and deceived are more than 600000. They are sent to  Sunwu by stuffy train to be coolie. The food is mould kaoliang and acorn meal with skin. Even  so, it is insufficient. The clothes are renewable clothes and gunny bag pieces. The houses are work sheds on the wasteland, it is as cold as the ice room in the winter.

  When working, the laborers were watched by the Japanese soldiers with the gun , supervised by the foreman with a pickaxe stick to beat if he disliked somebody. If the horrible living situation and the heavy labor made laborers sick, then they would be abandoned in the wasteland as an infectious one. To keep secret, some laborers who had done the special work would be slaughtered collectively. There are at least six mass graves and one smelt person works in Sunwu county. The graves of the laborers are difficult to find, but the spirit of the laborers complains the Japanese in the wild for ever.   

 the ruin of Sunwu fort of Japanese army