1. A method of providing a distributed service composition model for service composition in an ad hoc network comprising a plurality of mobile networks, the method comprising: confirming whether an adjacent mobile node exists within a number of hops from a task initiator node so as to execute a task; establishing a flow for executing the task with regard to the adjacent mobile node if it is confirmed that the adjacent mobile node exists; and executing the task using a routing algorithm in accordance with the flow, wherein at least one service necessary to execute the task and an execution order between services are determined based on cooperation between adjacent mobile nodes.