Investors were also disappointed after a key Communist Party meeting last week ended without any announcement of major policies to support the slowing economy, analysts said.
The Shanghai Composite Index ended down 0.5 percent at 2,290.42 points, while the CSI300 of the leading Shanghai and Shenzhen A-share listings lost 0.9 percent.
Financials were the main drags on the mainland market with CITIC Securities and Haitong Securities, the country's two biggest listed brokerages, both down 2.8 percent.
The stock trading agreement between Hong Kong and Shanghai - hailed as a milestone to open up China's markets to global investors - will not be launched this week as initially expected because it has not yet won regulatory approvals from either side, Hong Kong stock exchange chief executive Charles Li said on Sunday.