The most important commitment of the seller in the legall systems is the delivery of the goods which the buyer contracts and certainly its rules are different.Because of the complications arisen from social and economical associations in the international trad stage and with due to the monotonousness of the rules which govern international sale contract and also the removal of the legall barriers, some documents have been approved in the international trade which Vienna convention in the most important one. This convention has been approved with due to the broad aims inserted in the approved menifestose of the sixth special session of the General assembly of United Nations on the stablishment of new universal order in 1980.According to these facts, comparative exiniation of this issue seems essential in this thesis, I compare the delivry according to the contract between Iranian law and viena convention in two parts, in the first part we study the conception of delivery in three sections and eleven chapters, here some issue has difinations, nature and delivery are examined. According to the contract and with due place, time, quality, quanity of the delivery and etc. In the last section of this part, we consider usage and its effect on commercial manner.In the second part we exmine the effect of delivery and non- delivery and sanctions in three sections and seven chapters and speak about some conceptions as force majeure, Hardship, passing of risk, rescission, Indermnity and etc.