As Chinese airlines expand their operations they often seek to access funding from local governments and to do so they often form joint ventures with them rather than just moving some aircraft to that location. This gives them access to new markets but minimises risks associated with obstructive local government bodies and startup losses. In recent years these regional semi-independent branches of the main carriers have been popping up all over the place including remote Inner Mongolia.
2012 August. Air China launches Inner Mongolia subsidiary. Air Transport World
2012, July. Air China's Inner Mongolia subsidiary approved. China Daily US
Airfleets: Air China Inner Mongolia
2014, June. Air China Inner Mongolia takes delivery of first B737-800. Ch-aviation