Abstract      Smart contracts offer a unique method of contracting that differs from the methods used for a long time in this regard; Because the agreement between the contracting parties appears in the form of a code that is run and executed by members of the Blockchain network or the nodes, without one of the parties being able to stop it; so that when a certain condition is met and the members of the network verify that, the related or the corresponding condition is executed automatically; therefore it's a contracting method that guarantees the process of contracts performance in the manner agreed upon, without the need to have a confidence in the other party or resort to a trusted body to verify the truth of that party or the object of contract; so we thought about studying the topic of the conclusion of those contracts in order to highlight their features and clarify the extent to which general rules accommodate the specificities of their formation; and we divided our research into an introductory section entitled "the fundamentals of block chain technology", and two main sections; the first entitled "the idea of smart contracts as a blockchain application", and the second entitled" specificity of smart contracts formation. Keywords: smart contracts, blockchain, DApps, Ethereum.