Robert Frank | @robtfrankCNBC.com
China created 40,000 new millionaires in 2013, bringing the total to 1.09 million, according to a new study.
The growth of 3.8 percent is a bit of an improvement from last year's 3 percent gain. But it's still only about half the growth rate of 2010 and 2011, suggesting that China's economic slowdown and the government's crackdown on corruption is slowing its millionaire manufacturing machine.
According to the Hurun Research Institute, the number of people in China with personal wealth of 10 million yuan—or $1.6 million—in mainland China reached 1,090,000, up from 1,050,000 in 2012. The number of people in China worth 100 million yuan, or $16 million, increased by 2,500 people to 67,000.
The slower millionaire growth comes as sales of high-end luxury goods in China—everything from watches and wine to handbags and Lamborghinis—have also cooled. But Rupert Hoogewerf, chairman and chief researcher of the Hurun Report, said this year's millionaire growth was still solid.
"Although we have been seeing a slowdown in spending, the money is still very much there," he said in the report.
The report said 55 percent of the millionaires are private business owners. One in 5 are senior executives at large companies and 15 percent are listed as "real-estate investors." Only 10 percent are described as "professional stock market investors," or those whose main source of income is stocks and financial investments.
Beijing and Guangdong have the most millionaires, with 192,000 and 180,000 respectively, followed by Shanghai with 159,000. Yet Shanghai had the fastest growth of millionaires, adding 12,000 millionaires in 2013. Beijing and Guangdong each added 8,000 millionaires, and Shenzhen added 4,000.
Estimating people's private wealth in China is a difficult task, given the lack of transparency and unreported wealth and income. Hurun Report said it uses a "bottom-up" and "top-down" approach, looking at sales of high-end real estate, sales volume of luxury cars, income-tax returns, the registered capital of companies and other high-end consumer indicators. It also uses measures of gross domestic product and gross national product.
—By CNBC's Robert Frank