In 2004, Korea deposited its instrument of accession to the United Nation Convention on the International Sales of Goods(CISG) with the Secretary-General of the United Nations. Following this development, the CISG entered into force, insofar as Korea was concerned, in March 2005. Therefore, the similarities and differences between the CISG and Korean Laws need to be examined. This study compares CISG with Korean Corporate and Civil Law about `offer and acceptance of Contact`. There are eight major difference about these CISG and Korean Laws. First, CISG applies on `place of business` but Korean Corporate law applies on `merchant`. Second, CISG defines about `Offer` and `Acceptance`. But there is no definition in Korean Corporate and Civil Law. Third is deal with a lack of contract`s main contents. Forth, CISG and Korean Civil Law differently regulate about offer`s withdrawal. Fifth, in CISG, silence or inactivity doesn`t admit in itself to acceptance. But Korean Corporate and Civil Law don`t define. Sixth, Battle of Form doesn`t define CISG and Korean Corporate and Civil Law. Seventh, there are some difference of view point between CISG and Koresn Civil Law on late acceptance. Final, Korean Corporate Law regulates obligation of notice. These differences are partly derived from both the reasonable character of the CISG and the defects in Korean Corporate and Civil Law. Thus, this study undergoes the imperative need to amend Korean Corporate and Civil Law in conformity with its obligations under the CISG.