From Official TOEFL Center in China (NEEA), TOEFL iBT register in July through October in China will be opened at 12:00 on April 28. the test dates will be:
July 7, 14, 28
August 11, 25
September 12, 15, 29
October 20, 21, 28
Here is the original news (in Chinese) from official TOEFL register website in China.