A Route Army was a type of military organization during the Chinese Republic, and usually exercised command over two or more Corps

Corps

A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...

 or a large number of Division

Division (military)

A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...

s or Independent Brigade

Brigade

A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

s. It was a common formation in China prior to the Second Sino-Japanese War

Second Sino-Japanese War

The Second Sino-Japanese War was a military conflict fought primarily between the Republic of China and the Empire of Japan. From 1937 to 1941, China fought Japan with some economic help from Germany , the Soviet Union and the United States...

 but was discarded as a formation type by the National Revolutionary Army

National Revolutionary Army

The National Revolutionary Army , pre-1928 sometimes shortened to 革命軍 or Revolutionary Army and between 1928-1947 as 國軍 or National Army was the Military Arm of the Kuomintang from 1925 until 1947, as well as the national army of the Republic of China during the KMT's period of party rule...

 after 1938 (other than the 8th Route Army), in favor of the Group Army

Group Army

A Group Army , is a major Chinese military organization. Some may use or translate it loosely to mean the same as Army Group and through various time periods or history, depending on whether the military formation is under Nationalist China or Communist China , Chinese Army Group or Group Army...

.

Some of the more famous of the Route Armies were:

• 8th Route Army Communist guerrilla force in North China.
• 19th Route Army
  Order of Battle January 28 Incident
  This is an Order of Battle for January 28 Incident. The Order of Battle is of the First Shanghai Incident, Battle of Shanghai 1932. This was a brief war between the armies of the Republic of China and the Empire of Japan that occurred prior to the Second Sino-Japanese War.- Japan :Shanghai...
  
   Defending Shanghai in 1932 during the January 28 Incident
  January 28 Incident
  The January 28 Incident was a short war between the armies of the Republic of China and the Empire of Japan, before official hostilities of the Second Sino-Japanese War commenced in 1937.- Naming :...
  
  .
• 29th Route Army Defending Hubei
  Hubei
  ' Hupeh) is a province in Central China. The name of the province means "north of the lake", referring to its position north of Lake Dongting...
  
   and Chahar
  Chahar (province)
  Chahar , also known as Chaha'er, Chakhar, or Qahar, was a province of China in existence from 1912 to 1936, mostly covering territory in what is part of eastern Inner Mongolia. It was named after the Chahar Mongolians....
  
   in July 1937 in the Marco Polo Bridge Incident
  Marco Polo Bridge Incident
  The Marco Polo Bridge Incident was a battle between the Republic of China's National Revolutionary Army and the Imperial Japanese Army, often used as the marker for the start of the Second Sino-Japanese War .The eleven-arch granite bridge, Lugouqiao, is an architecturally significant structure,...
  
   and Battle of Beiping-Tianjin
  Battle of Beiping-Tianjin
  The Battle of Beiping-Tianjin , also known as the “Peiking-Tientsin Operation” or by the Japanese as the was a series of battles of the Second Sino-Japanese War fought in the proximity of Beiping and Tianjin...
  
  .

Source

• Hsu Long-hsuen and Chang Ming-kai, History of The Sino-Japanese War (1937-1945) 2nd Ed. ,1971. Translated by Wen Ha-hsiung, Chung Wu Publishing; 33, 140th Lane, Tung-hwa Street, Taipei, Taiwan Republic of China.