Pope Francis is to make public the conclusions of his two Synods on the family in a document eagerly awaited by 1.3 billion Roman Catholics, BBC reported.
It will detail the pope's views about family life, marriage, contraception and bringing up children.
Many hope it will open the way for the church to offer communion to the divorced and civilly remarried, something conservatives have resisted.
The document is the culmination of three years' work by the Pope.
BBC religious affairs correspondent Caroline Wyatt says that what is known as an Apostolic Exhortation is a wide-ranging document of more than 200 pages entitled The Joy of Love.
The Pope sent a questionnaire to families across the world asking them about their hopes and their fears.
Then he brought bishops and cardinals together for two Synods in Rome, at which he encouraged them to debate and even to disagree over issues that divide the church in many countries.
Those range from offering communion for the divorced and remarried, contraception and the treatment of Catholics who are gay.
Our correspondent says the lengthy document will show exactly where Pope Francis stands - with some already describing it as a Papal bombshell - as he steps into the minefield of Catholic teaching on the family.
While conservatives do not want him to change doctrine, liberals hope he will tell the church to show a more merciful attitude to those whose families do not conform to the current Catholic ideal.