Contemplating the victory of war from Sun Tzu's“Art of War＂requires profound and diverse battle plans and stratagems. For example, the clever combatant imposes his will on the enemy, but does not allow the enemy's will to be imposed on him; through the enemy we learn to be invisible and inaudible; we should keep our forces concentrated, while keep enemy's force separated; making scheme so as to discover battle plans and the likelihood of success, and thus learn the principle of his activity or inactivity; forcing the enemy to reveal itself in order to find out its vulnerable spots; and military tactics are like unto water. The Art of War has well interpreted and described the essence of war. The chapter“Weaknesses and Strengths＂of Sun Tzu's masterpiece“Art of War＂adopts initiative campaign as the principle and uses the concept of avoiding enemy's strength and attacking enemy's weakness. Various kinds of measures are utilized to force the enemy maintaining in inferior situation, then build up advantageous situation for ourselves in order to gain superiority; therefore enemy can be defeated. This concept is similar to“Concentrate troops at a strategic point＂and“Indirect Approach＂proposed by the western military strategists Jomini and Liddle Hart respectively. The Battle of Shanghai plays a pivotal role during the eight-year Sino-Japanese War with the aim to force the Japanese force to disperse, thus shift enemy's concentration of operation in order for the Chinese force to create a sustainable and advantageous condition for a protracted war. This conforms to Sun Tzu's“Weaknesses and Strengths＂Owing to lack of understanding of“Weaknesses and Strengths＂, Japanese force did not concentrate its superiority on the strategic decisive point. Therefore, despite Japan won the Battle of Shanghai, it eventually lost the Eight-Year War.