1972. Judge, Daejeon District Court
1977. Judge, Incheon Branch, Seoul District Court
1977. Gottingen University, Visiting Schollar
1978. Judge, the Seoul Civil District Court
1980. National Court Administration
1981. Judge, Seoul High Court
1982. Judicial Researcher, Supreme Court
1984. Presiding Judge, Busan District Court
1986. Presiding Judge, Seoul Criminal District Court, National Court Administration
1989. Chief, Supreme Court Library of Korea
1991. Presiding Judge, the Seoul Civil District Court
1992. Presiding Judge, Busan High Court
1993. Presiding Judge, Seoul High Court
2000. Chief Judge, Daejeon District Court
2000. Justice, Supreme Court of Korea
2001. Minister of National Court Administration
2006. Legal Advisor, BAE, KIM & LEE
2007. President of Constitutional Court
2015. Attorney, Hangeol
2019. Legal Advisor, CLASS