Gao Zhisheng's wife says authorities will free the human rights expert in around three weeks.
He was well known in the country for standing up for Christians in court until 2006 when the government jailed him for "inciting to subvert the state power."
After his release Gao disappeared while visiting his in-laws in Xinjiang. On 16 December 2011, the Chinese news agency Xinhua reported that Gao had violated the terms of his probation and had been returned to prison for three years.
There are worries about how free Gao will be when he is released amid claims he could be subject to conditions or restrictions.
Chief Executive of Christian Solidarity Worldwide, Mervyn Thomas, said: "We welcome the news from the prison authorities that Gao Zhisheng will be released on 7 August.
"At the same time, we share the concerns of Gao's family about the details of his release and the possibility of further restrictions on his freedom.
"We believe that lawyer Gao was targeted for his advocacy for the rights of religious minorities and other vulnerable groups, and further note the many incidences of extra-legal measures against Gao since 2006, including enforced disappearance and torture in detention.
"We call on the Chinese authorities to release Gao Zhisheng on 7 August without any further restrictions on his freedom."