According to the data, the total number of Catholics in the country is 5,004,115: This is 9.9% of the population, an increase of 130 thousand units compared to previous data. The local clergy, moreover, is equal to 4204 units, compared to 4026 previously reviewed: of these, 3477 are diocesan priests, 726 are missionaries or religious. The number of seminarians remains essentially the same, with 1413 compared with 1445: however of these, many become priests. The number of women religious has grown by 186, reaching 10,401.

Compared with the results of the general census of 2005, which the government makes every ten years, Catholics have grown by 74% against an 18% increase in Buddhists and a 16% decrease in Protestants. The data reflected the Christian denominations, which were questioned about their way of doing mission in the Asian country.  

The professor Kim Jong-seo, who teaches science of religion at the Seoul National University, analyzed the reasons for the success of Catholic evangelization in Korea. According to the teacher, there are six key points that have enabled this result:  

Unity and hierarchical organization. The South Korean Catholic Church is organized into sixteen dioceses led by ordinary bishops, which all respond to the Conference of Bishops. This, in turn, is divided into six commissions and 20 committees. The Whole Church functions as an organic body under hieratical leadership, which has made a favourable impression on the Korean people.

Integrity living a life of integrity is important for Korean clergy and consecrated persons. Administration of financial affairs of the dioceses and parishes is conducted in a transparent way at all levels, which has given good image of Catholic Church to Korean people.  

The commitment to justice and peace The Korean Catholic Church has played an important and prophetic role during almost three decades of democratization, under the persecution of the military regime since 1960s. Numerous priests, religious and lay faithful including the late bishop Daniel Ji Hak-sun were imprisoned and tortured for fighting against injustice and siding with the weak in society. Nowadays, the whole Church including the Catholic Priests’ Association for Justice (CPAJ) and other Catholic NGOs are very much involved in environmental, ethical and social issues and the promotion of the human rights.

Tolerance towards ancestral rites.  In 1742, Pope Benedict XIV prohibited devotion to ancestral rites condemning them as superstition, thus providing China and Korea an excuse to persecute Christians. But in 1939 pope Pius XI decided to allow the Confucian ancestral rite under the condition all superstitious elements were removed. Something the Protestant Church does not allow.

An open attitude toward the other religions.  While some religions are unfriendly to other religions the open attitude of Catholic Church to other religions gives favourable impression to non-Catholics. This is the result of Vatican II which opened the Korean Chuch to others.  During the military different religions collaborated for the democratisation of the nation.

Social commitment. Under the guidance of their bishops Korean Catholics are committed to the poor and this has given much impetus to evangelization. The fact that this commitment is open to all - irrespective of nationality, race or creed - shows the goodness of primary teaching that is the basis of Catholicism.