The number of millionaires -- defined as those with personal wealth of at least 10 million yuan ($1.6 million) -- rose just three percent year-on-year to 1.05 million, said the independent Hurun Research Institute and consultancy GroupM Knowledge.
The number of "super-rich" Chinese -- with personal wealth of at least 100 million yuan -- went up only two percent to 64,500, also the slowest pace in five years, according to the survey released on Wednesday.
The slowdown came as growth in the world's second largest economy slipped to a 13-year low of 7.8 percent in 2012.
Only a quarter of Chinese millionaires were "very confident" about the domestic economy in the coming two years, the survey showed, down from 28 percent in 2011 and nearly half of those questioned in 2010.
China's economic growth slipped further to 7.7 percent in the January-March period this year and slowed to 7.5 percent in the second quarter, raising alarm bells over possible deeper weakness.
Beijing, the nation's capital and political centre, had the highest number of millionaires with 184,000, or 17.5 percent of total, the survey said, ahead of the financial hub Shanghai on 147,000.
Stock market sluggishness also contributed to the slower growth of the wealthy population, with the Shanghai exchange's benchmark index gaining only 3.17 percent last year.
About 15 percent -- 160,000 -- of Chinese millionaires named stock investments as their main source of wealth, down five percent from 2011, according to the survey.
Real estate remained Chinese millionaires' top investment choice despite government regulations aimed at cooling the market, the survey said, but they had a growing tendency to seek such investments overseas.