A communication terminal comprises a storage unit, a selection unit, and a communication unit. The storage unit stores electronic data and condition information indicating a selection condition of the electronic data. The selection unit selects the electronic data from among the electronic data stored in the storage unit and the electronic data indicated by possession information indicating the electronic data possessed by other communication terminals joining data sharing based on the condition information. The communication unit receives the possession information from the other communication terminals between a first timing and a second timing when the selection unit selects the electronic data.