The first flight direct from the Chinese megacity of Chongqing landed at Heathrow over the weekend.
Tianjin Airlines introduced three flights a week on the route and is expected to carry up to 81,000 passengers a year.
The carrier is using an Airbus A330-200 for the service, with departures from the London hub on Tuesdays, Wednesdays and Saturdays.
A total of 2.8 million passengers travelled directly to and from China from Heathrow last year, an increase of nearly 2% from 2016.
While connections to Chinese cities are valuable to the UK,
However, rival EU hub airports with spare capacity are able to connect directly to eight other Chinese destinations, including mega cities like Hangzhou, Chengdu, and Kunming.
Heathrow has been able to accommodate five new Chinese destinations this year in what it described as a “limited and piecemeal approach”.
Expansion of Heathrow will give the UK the opportunity to build “vitally important” connections to China the country needs, the airport claimed
Chief commercial officer Ross Baker said: “We are tremendously pleased to welcome our tenth direct connection to China – and direct link to some of the most stunning scenery and culinary experiences China has to offer.
“Heathrow is proud of its role as the UK’s Hub airport and biggest gateway for Chinese passengers and cargo going between our two countries.
“But we have much further to go, and now that Parliament has voted unequivocally in favour of Heathrow expansion we will ensure London, and the UK, become the destination of choice for Chinese trade, tourism, and investment.”