Japanese Army

-1870, consisted of 12,000 men.
-1885, consisted of seven divisions including the Imperial Guard Division.
-In the early 1900s, the IJA consisted of 12 divisions, the Imperial Guard Division, and numerous other units. These contained the following:
380,000 active duty and 1st Reserve personnel - former Class A and B(1) conscripts after 2 year active tour with 17 and 1/2 year commitment
50,000 Second line Reserve - Same as above but former Class B(2) conscripts
220,000 National Army
1st National Army - 37 to 40 year old men from end of 1st Reserve to 40 years old.
2nd National Army - untrained 20 year olds and over 40 year old trained reserves.
4,250,000 males available for service and mobilization.
-1934 - army increased to 17 Divisions
-1940 - 376,000 active with 2 million reserves in 31 divisions
2 Divisions in Japan (Imperial Guard plus one other)
2 Divisions in Korea
27 Divisions in China and Manchuria
-In late 1941 - 460,000 active in 41 divisions
2 divisions in Japan and Korea
12 divisions in Manchuria
27 divisions in China
plus 59 Brigade equivalents.
Independent brigades, Independent Mixed Brigades, Cavalry Brigades, Amphibious Brigades, Independent Mixed regiments, Independent Regiments.
-1945 - 5 million active in 145 Divisions (includes 3 Imperial Guard), plus numerous individual units, with a large militia
includes Imperial Japanese Army Air Service.
Japan Defense Army in 1945 had 55 divisions with 2 million men.
-Total military in August 1945 was 6,095,000.


Source
http://en.wikipedia.org/wiki/IJA