The Jixiao Xinshu (simplified Chinese: 纪效新书; traditional Chinese: 紀效新書; pinyin: Jìxiào xīnshū) or New Treatise on Military Efficiency is a military manual written during the 1560s and 1580s by the Ming dynasty general Qi Jiguang. Its primary significance is in advocating for a combined arms approach to warfare using five types of infantry and two type of support. Qi Jiguang separated infantry into five separate categories: firearms, swordsmen, archers with fire arrows, ordinary archers, and spearmen. He split support crews into horse archers and artillery units. The Jixiao Xinshu is also one of the earliest-existing East Asian texts to address the relevance of Chinese martial arts with respect to military training and warfare. Several contemporary martial arts styles of Qi's era are mentioned in the book, including the staff method of the Shaolin temple.

In the late 16th century the military of the Ming dynasty was in poor condition. As the Mongol forces of Altan Khan raided the northern frontier, China's coastline fell prey to wokou pirates, who were ostensibly Japanese in origin. Qi Jiguang was assigned to the defense of Zhejiang in 1555, where he created his own standards of military organization, equipment, tactics, training, and procedures. He published his thoughts on military techniques, tactics, and strategies in the Jixiao Xinshu after achieving several victories in battle.

There are two editions of the Jixiao Xinshu. The first edition was written from 1560-1561 and consists of 18 chapters. It is known as the 18-chapter edition. The second edition, published in 1584 during Qi's forced retirement, included re-edited and new material compiled in 14 chapters. It is known as the 14-chapter edition.

The chapters included in the 18-chapter edition are as follows:

In the Jixiao Xinshu, Qi Jiguang recommended a 12-man team known as the "mandarin duck formation" (Chinese: 鴛鴦陣; pinyin: yuānyāng zhèn), which consisted of 11 soldiers and one person for logistics.

The mandarin duck formation was ideally symmetrical. Excluding the corporal and cook/porter, the ten remaining men could be split into two identical five-man squads. This was so that when Japanese pirates made it past the long lances, the saber-and-shield men formed a protective screen for the vulnerable lancers. In battle, the two saber-and-shield men had different roles. The one on the right would hold the advance position of the squad, while the one on the left was to throw javelins and lure the enemy closer. The two men with multiple-tip spears would entangle the pirates while the lancers attacked them. The trident carriers guarded the flanks and rear.

After suffering several defeats to pirates, Qi also made a recommendation for a concerted campaign to integrate musket teams into the army, based on their superior range and firepower compared to bows and arrows. Qi became enamored with the musket (bird gun) after his defeats and became one of the primary proponents of their use in the Ming army. He favored it for its accuracy and its ability to penetrate armor.

Ideally an entire musket team would have ten musketeers, but often had four or two in practice. The optimal musket formation that Qi proposed was a twelve-man musket team similar to the melee mandarin duck formation. However, instead of fighting in a hand to hand formation, they operated on the principle of volley fire, which Qi pioneered prior to the publication of the first edition of the Jixiao Xinshu. The teams could be arranged in a single line, formed two layers deep with five musketeers each, or five layers deep with two muskets per layer. Once the enemy was within range, each layer would fire in succession, and afterwards a unit armed with traditional close combat weapons would move forward ahead of the musketeers. The troops would then enter into melee combat with the enemy together. Alternatively, the musketeers could be placed behind wooden stockades or other fortifications, firing and reloading continuously by turns.