The following year he moved it to Vietnam to try to avoid detection by police.
Players on the site, games998.net, exchanged real money into game coins to participate in dozens of gambling games from mahjong to poker, the Legal Daily newspaper reported last year.
According to investigators more than two million people signed up and bought 400 billion yuan ($58 billion) in game coins, Xinhua said.
The operators made profits of 580 million yuan.
Zhou, 47, was arrested in Vietnam and repatriated. His trial began on Thursday in Songyang, in the eastern province of Zhejiang, charged with setting up the online casino.
Eight of Zhou's accomplices were sentenced in an earlier case and several are still at large, Xinhua said.
Gambling is illegal in China, except in state-sanctioned lotteries.