China's Catholics number between 8 and 12 million and are divided between the state-sanctioned Catholic Patriotic Association, which has installed bishops without Vatican approval, and an "underground" wing loyal to the Vatican that rejects state control.
Francis's predecessor, Pope Benedict XVI, made May 24 a day dedicated to prayer for China's Catholics.
Francis said at his weekly audience in St. Peter's Square that he prayed that China's Catholics would receive "the grace to announce Christ with humility and joy and to be faithful to the Church and to Peter's successor (the pope)".
China and the Vatican broke off formal diplomatic relations shortly after the Communists took power in China in 1949.
Benedict had encouraged the two sides of the divided Chinese Church to reconcile, and engaged in a low-key dialogue with Beijing about political ties.
But last July the Vatican condemned the appointment of a Chinese Catholic bishop without its approval. One of Rome's own newly ordained bishops, Thaddeus Ma Daqin, has been held under house arrest since he announced around the same time that he was leaving the Catholic Patriotic Association.
The Vatican has previously condemned what it called "external pressures and constrictions" on Catholics in China.