There are situations in e-commerce that are altogether new and to which the existing rules cannot apply. The uncertainty and business risk is too high for trading partners to deal with certainty. Therefore existing law must be changed to e-commerce law so that it provides certainty and enforceability in the e-commerce. Legal rules applying to the commerce and international commerce, in particular, contracts, proper law, jurisdiction and so on, have improved with time and experience. It has been found that the problems arising in the context of e-contracting were due to the absence of experience in electronic contracting and an absence of knowledge on how best to solve the problems. Thus, UNCITRAL Working Group on Electronic Commerce held an extensive discussion on issues related to electronic contracting and prepared and revised the Preliminary Draft Convention on International Contracts Concluded or Evidenced by Data Message from the thirty-ninth session in 2002 and prepared the Draft Convention from forty-first session which applies to international contracts concluded or evidenced by means of data messages. An electronic contract is concluded when the acceptance of an offer becomes effective, and an offer becomes effective when it is received by the offeree, and an acceptance of an offer becomes effective when the indication of assent is received by the offeror according to this Convention. Electronic contract may be concluded by the interaction of an automated computer system and natural person or by the interaction of automated computer systems, and a contract formed by a natural person that accesses an automated computer system of another person has no legal effect in case the neutral person made a material error in a data message. The purpose of this paper is to raise the understanding of the Convention on the Electronic Contracting by studying the contents of Draft Convention on Electronic Contracting and comparing Draft Convention with preliminary Draft Convention and finding the difference, characteristics and problem.