The Shanghai Composite Index closed down 1.1% at 3,664, losing 10% over the week and more than 14% for the month.
The government took further action to calm the market on Friday with a crack down on automated trading.
It restricted 24 trading accounts in which it had detected what it called abnormal bids, moves it described as malicious selling.
Hong Kong's share market headed in the opposite direction, with the Hang Seng index finishing up 0.6% to 24,636.28 points.
Investors are looking ahead to China's official manufacturing data, which is expected to be released over the weekend.
A private manufacturing report last week showed a surprise drop, prompting a plunge in mainland China's shares earlier this week.
In Japan, shares were held back as data showed inflation stalling and an unexpected fall in household spending.
The country's benchmark Nikkei 225 index closed slightly higher at 20,585.24 points, up 0.3%.
Japan's inflation in June remained at 0.4% while household spending dropped by 2%, significantly more than expected.
The weak data is likely to revive deflation fears and increase the pressure for more fiscal policy and monetary easing.
Shares in technology giant Sony fell by 1.5% despite the company releasing strong results on Thursday after the Japanese stock market had closed.
The company saw its net profit more than triple in the April-to-June quarter, helped by strong sales of its PlayStation 4 games and camera sensors.
In South Korea, positive data on business confidence and industrial production lifted shares.
The Kospi index closed 0.5% higher at 2,030.16 points.
Australia's ASX 200 finished 0.5% up at 5,699.20 points.
Mainland Chinese shares ended July with their biggest monthly loss in nearly six years.