The UK and the People's Republic of China were on opposing sides of the Cold War, while the Republic of China and the UK were allies during World War II. Both countries are permanent members of the United Nations Security Council.
Today, however, China and Britain enjoy a friendly, cooperative, and close relationship. China and Britain have established a full strategic partnership and close cooperation, this is currently being consolidated by the chancellor‘s visit to Beijing the capital of China.
The reason being China acting as a powerhouse. Its economy now is over three times what it was in 2005. While the UK and most other developed countries suffered during the great financial crisis from 2008, the country that exists now has an emerging middle class, working in the services sectors, living in the vast new cities being renovated or simply built from scratch, whose future patterns of consumption will be crucial for global growth.
Like it or not, China supports the unity the EU offers, at least financially and economically, and while it would never publicly state anything on this, it would almost certainly regard a UK exit negatively one would presume.
The UK as an intellectual partner of China, as it attempts to build a new kind of economic structure and deal with some of its huge environmental and sustainability issues, is a new kind of role, and one of the few where it can be liberated from the shadow of its historic issues with the People's Republic.
I have already mentioned their stock market crash caldariborderzone.blogspot.co.uk/2015/09/chinas-bad-month.html so no need to revisit that, but what about human rights? Well that is another matter entirely...