The Shanghai Composite fell 0.2% toward 3,380 while the Shenzhen Component lost 0.1% to 10,165 on Thursday, erasing gains from the previous session as escalating geopolitical tensions weighed on global sentiment.
Markets were rattled by reports that US officials are preparing for a possible strike on Iran, which could happen over the weekend.
Iran's Supreme Leader Ayatollah Ali Khamenei also warned of "irreparable damage" to the US if it intervenes in the Israel-Iran conflict.
Domestically, investor sentiment was further dampened by a lack of fresh policy signals from top regulators speaking at the Lujiazui Forum.
Markets now turn their focus to the upcoming July Politburo meeting for stronger economic support measures.
Meanwhile, the People's Bank of China is set to announce its latest loan prime rate decision later this week, with expectations for no change.
Among individual stocks, notable losses included Huafon Microfibre (-5%), Hebei Changshan (-12%), and Rongfa Nuclear (-6%).

Sumber : tradingview.com