He joined the Fengtian Army in 1917, as a private soldier and rose to platoon leader, then captain over the next sixteen years.
At first, the CCP severely criticised their conduct yet the stance of the party prevented the growth of their own forces and did not help the anti-Japanese cause.
In 1933, when Wang was defeated by the Japanese and fled Manchuria, Li remained with the remnant NSA forces, now dispersed in small guerrilla bands.
There he organized a unit from former NSA troops for the Northeastern People's Revolutionary Army in the Ning'an area and continued the struggle against the Japanese.
In 1935, when the CCP officially changed policy and began creating a united front, the army welcomed and absorbed most of the remaining anti-Japanese forces in Manchuria.