In order to check whether you are allowed to enter Korea without visa issuance and for other requirements, please contact a Korean embassy or consular office in your country or visit the following websites to confirm.
Ministry of Foreign Affairs
www.mofa.go.kr (Korean, English)
Korea Immigration Service
www.immigration.go.kr (Korean, English)
www.hikorea.go.kr (Korean, English, Japanese, Chinese)
World Travel Guide