It would appear that driving on the left was the convention in China until January 1, 1946. Presumably the change was influenced by America advisors on the government in Chungking.
South China Morning Post & Hong Kong Telegraph, 6 January 1946
TRAFFIC CONFUSION
Canton Inconvenienced By Change-over
Canton, January 2
Canton streets are a source of danger today, as motor drivers are confused by the new ruling of driving to the right. Rickshaw coolies are also new to this experience and find themselves at times running on the wrong side of the street.
There were several minor traffic accidents owing to the “Americanisation” of street traffic, in conformity with a national order issued from Chungking. Buses are overcrowded because many of them are laid up to undergo repairs-changing the exits from left to right. There are no regular stops, and the drivers halt at any place they please.
The local authorities order pedestrians to keep to the pavement but in most shopping districts the pavements are occupied by hawkers. Still in New Year mood, the streets are full of people. Ladies with gorgeous dresses prefer to take the middle of the street to give a better display.
During the Jap regime, streets were poorly kept. An American pilot taking a bus ride just for fun said in some parts of the city the vehicle jumped like a bronco and that the ride reminded him of flying over the “Hump”.