China is expected to surpass the U.S. as the world's top retail market in 2019, according to a report out this week from market research firm eMarketer.

The world's most populous country is expected to see its total retail sales grow by 7.5 percent this year to $5.6 trillion, compared to 3.3 percent growth in the U.S. retail market to reach $5.5 trillion.

Along with Chinese consumer's rising disposable incomes, there's also been rapid economic growth in second- and third-tier cities in China.

Yet according to recent data, Chinese consumers are spending less, as many are concerned about the future. China's economy, meanwhile, grew 6.6 percent last year, which was the slowest pace in 28 years.

While the retail sales growth rate for both U.S. and China are slowing, the Chinese growth rate is expected to exceed the U.S. growth rate through 2022, according to the eMarketer report.