I’ve been warning of luxury slowdown throughout the summer. And the reason can be explained in a single word: China. For the past three years, China and Chinese tourists shopping abroad have filled the gap in the luxury market left by the Americans and Europeans. China is now the world’s second largest market for luxury goods, behind Japan. Despite the current slowdown in China’s economy, the country’s luxury market is expected to top $12 billion this year. But that support may be slipping. After Burberry’s earnings warning this morning, it’s stock fell 18 percent. Other lux stocks fell in sympathy, including LVMH, Hermes and Richemont. It’s unfair to lump these all of these companies together, especially as the luxury market bifurcates into strong high-end brands and weaker mass- luxury marketers. And some are run better than others. Hermes, for example, should not be punished for the retail strategies of Coach and Burberry. But all of these luxury companies share a common problem. They have all become dependent on China. And China is slowing. (Read more: Long Luxury Boom Slows in China) Robert Frank CNBC Reporter & Editor As David Faber said on our air this morning: “Chinese high rollers are just not rolling as high.” China’s next leader is missing, and so is China’s luxury consumer. The signs first appeared in the Spring, with some disappointing wine auctions. It then spread to bigger ticket items: jets, yachts and fine art. Overall, auction sales this spring fell 43 percent compared to the fall of 2011. Weak demand is also showing up in prices. The Chinese luxury CPI, which tracks prices for everything from there hes to G550 jets to Zegna suits and Patek Philippe watches, is now growing at about half the rate of 2011. The price of golf villa in Shanghai have fallen 7 percent this year, to $3 million. (Read more: China’s Art Bubble May Be Popping ) Some of this is due to a slowing economy in China and the end of stimulus. But it’s also due to a broader backlash against luxury and the wealthy in Chinese society and government. The Chinese word for “luxury” is discouraged on billboards. A blogger using the name Huazong has become a web sensation by the tracking the luxury watches worn by government officials making modest official salaries. He tracked watches for 2300 officials last year. A “discipline inspection commission” is investigating the assets of a government official who was shown online to be wearing – at various times — five different luxury watches, even though is official salary was less than $1,500 a month. When luxury can get you investigated, it may be time to rethink the Chinese luxury boom.