To understand the procedure of international commercial transaction clearly and logically, this author would like to emphasize the contractual approach in this paper. The main contract in the transaction is the contract of sale; to perform this contract, the three subordinate or supporting contracts(including the contract of carriage, the contracts of insurance and the contract of payment) should be followed and performed. In the contract of sale, besides the express Terms, the trade Terms have very comprehensive meanings. Each trade term in Incoterms(2000) deals with the matters relating to the rights and obligations of the parties to the contract of sale with respect to the delivery of the goods sold. It also provides for the duties of seller or buyer relating to the contract of carriage, the contract of insurance and the payment in the process of the delivery of goods. Especially, it does not provide the methods of payment concretely, but it imposes the seller to hand over the documents evidencing the conformity of the contract of sale, and the delivery which includes the documents of carriage and/or insurance. Thus although the trade Terms deal with the obligations of the seller or buyer directly, they are very closely related with the contract of carriage and the contract of insurance indirectly, and also with contract of payment using the documentary draft. For the Arbitration or the litigation in the case of the breach of contract, the trade Terms play very significant roles. When an arbitrator or a judge decides the case, they should understand each obligation clearly, in which case, the trade terms give answers about who is wrong or who is right. Therefore, the contractual approach focusing on the trade terms would give very fruitful advantages to the students or teachers in understanding the procedure of the international commercial transaction systematicly and comprehensively.