The origin of Korean culture can be traced back to nomadic civilizations in central Asia. We thus find in Korean religious traditions related to Siberian shamanism, worship centered on heaven and traditions of self-cultivation as a tradition of training. Beginning around the second century before the common era,through the importation of the Chinese writing system, Koreans were able to adapt Sinitic religions, philosophies, cultural artifacts, and institutions, resulting in a total transformation of Korean culture. It was during this period that Buddhism, Confucianism, and Daoist elements took root in Korea.
These three religions co-existed with shamanism for most of Korean history prior to the establishment of the Joseon dynasty in 1392. The Joseon Dynasty championed Neo-Confucianism as its philosophy of governance and officially suppressed Buddhism and shamanism. Though censored by the Korean state, Buddhism and Shamanism were able to survive through the support of female believers. The late Joseon dynasty witnessed the transmission of several forms of Christianity. Catholicism was introduced in 1631 and Protestantism was transmitted in 1884. This transmission also precipitated major changes in Korean culture and religion.
According to the 2005 Korean census, 53.08% of the population claims to be religious. 22.8% are Buddhist,29.26% are Christian (Protestantism makes up18.32%, Catholicism comprises 10.94%), 0.44% are Confucian, and other various religions amount to 1%. The activities of Christian is more active than Buddhist, so you will meet more Christian than Buddhism in Korea.