All references to "mothers and fathers" in the civil code, which enshrines French law will be swapped out for the term "parents."
The law also gives equal adoption rights to homosexual and heterosexual couples.
"Who is to say that a heterosexual couple will bring a child up better than a homosexual couple, that they will guarantee the best conditions for the child's development?" Justice Minister Christiane Taubira told France's Catholic newspaper La Croix.
"What is certain is that the interest of the child is a major preoccupation for the government."
Cardinal Philippe Barbarin, the head of the French Catholic Church has warned the faithful that same sex 'marriage' could lead to legalized incest and polygamy in society.
"Same sex 'marriage' would herald a complete breakdown in society," the cardinal told the Christian's RFC radio station.
"This could have innumerable consequences. Afterward they will want to create couples with three or four members. And after that, perhaps one day the taboo of incest will fall."
Leading French Catholics have also published a "Prayer for France," which says: "Children should not be subjected to adults' desires and conflicts, so they can fully benefit from the love of their mother and father."
In response, Pope Benedict has invited 30 French bishops to Italy to urge them to fight against the new law. "We have there a true challenge to take on," he said.
"The family that is the foundation of social life is threatened in many places, following a concept of human nature that has proven defective."
Leading French Bishop Dominique Rey has called on the government to hold a referendum on same sex 'marriage'.
"A referendum must be held to allow a real debate and to make sure the government is not in the grip of the lobbies," Rey declared.
"A majority of the population agrees with the traditional view of marriage."
President Francois Hollande pledged in his manifesto to legalize same sex 'marriage'. The draft law will be presented to his cabinet for approval on October 31.