The latest report from China’s Books and Periodicals Distribution Association tells us China finished the year with 225,000 bookstores and outlets, up 4.3% on 2017, with total sales revenue of 370.4 billion yuan ($54.7 billion), up 5.9% on 2017.

The Chinese government has played a big role in supporting publishing recently, as Xinhua reports:

Private bookstores played a significant part in the development, as 85 of the over 160 popular Sisyphe Bookstore chain as of October last year were opened in 2018 alone, and Yanjiyou, another popular brand, opened another 53 bookstores from January to November last year, according to an article on Wednesday’s People’s Daily.
According to the paper, the revitalisation of bookstores in China was largely due to favorable policies unveiled in recent years. After a national guideline on supporting the bookstore industry was issued in 2016, 28 provinces, autonomous regions and municipalities also released relevant policies to boost the industry.
For instance, 50 million yuan of subsidies has been distributed to 151 bookstores in Beijing since the release of the local guideline in July 2018.

As yet this story does not have enough meat to make any firm assertions about the Chinese publishing industry, generally regarded as second to the US.
But given the boost in government support and subsidies, and factoring in digital revenue, we may be looking at the first signs that China has bumped the USA to become the biggest publishing market.
That may not be as far-fetched as it at first sounds.
With a population of 1.4 billion and 800 million internet users it was always just a matter of time, and the October 2017 BookMap estimate of the global book market at $143 billion attributed just over $40 billion to the USA.

Global book market valued at $143bn

That of course for the 2015-16 book market.
Since when we have seen any number of indicators that China’s publishing industry has been growing by leaps and bounds while the US is at best stable.
The scenario of China as the world’s biggest publishing market becomes all the more plausible when we factor in digital, which in 2015 was barely off the ground in China but is now a huge contributor to the publishing sector.
We’ll need more than this one-off report from the Books and Periodicals Distribution Association to be sure, but it’s certainly a plausible scenario that China starts 2019 the world’s largest publishing nation both by output and by revenue.