The Chinese mainland will become the world's largest theme park market by 2020, when the number of visitors is expected to exceed 230 million, according to a report by US engineering firm AECOM.

The number of visitors to Chinese theme parks grew by an average annual rate of 13 percent in the past decade to reach 190 million in 2017. Double-digit growth is likely to be maintained in the coming years, according to the report.

The report attributed the rapid growth to rising incomes, which it said had pushed up consumer demand for leisure activities and more convenient public transportation systems.

But the report also found that China has a markedly lower per-capita attendance rate compared with developed economics.

"These findings demonstrate a significant opportunity for future growth in the Chinese market," said Chris Yoshii, vice president for Asia and global director for leisure and culture with AECOM.  

Most of the theme parks are in economically developed areas such as South China and East China, with the latter accounting for more than 30 percent of the total number, while more parks are being built in Central and Southwest China, the report showed.