Years before the WWII would break out in Europe the forces of Imperial Japan were fighting to dominate Chinese territory. The National Revolutionary Army did their best to fight back the invading Japanese military as they made their advance on Chinese territory. However, it might come as a bit of a shock to learn that the Chinese were using German tanks and other weaponry to fight back the Japanese.
This mainly has to do with a key figure in the German Wermarcht named Hans von Seeckt who was dispatched to China in 1933. There he used his experience to create a small well-trained military force rather than a large unprepared army concentrating the resources where they were needed most. Hans von Seeckt was no slouch when it came to building a military, he wanted the best officers and best equipment that he could get his hands on. Chinese equipment was not suitable for his high-standards so German military equipment was brought in to arm the National Revolutionary Army.
German military advisors present in China before the WWII broke out and before Japan had forged a partnership with Nazi Germany. This created a small rift between the two Axis nations and Japan demanded that Germany remove their military personnel from China. Hitler wanted not wanting to create tensions with Japan complied and all German military personnel was removed from China.
However, removing military vehicles as well as heavy weaponry proved to be a little more difficult since it was in the heat of battle. Thus the reason why the Chinese military used tanks and other such weapons from Germany. This short video from Military History Vlogs provides supplemental information about the Panzer tanks in China.