 Korea Semi-professional Football League was a semi-professional football league between corporate teams in South Korea from 1964 to 2002.In 1983, with the establishment of K League which is a professional league, Semi-professional League became the second tier and remained until 2002 before Korea National League was officially founded in 2003.The third tier K3 League was founded as an amateur league in 2007, and became the fourth tier after K League 2, the second division of the professional league, was founded in 2013.