According to the store-carry-forward method in Opportunistic Networks, the status on data transmitting has the relationship with the selection of relay node, and the distributed estimating results can make the assistance on the designing on effective data forwarding mechanism. A novel method to estimate delivery probability of data is proposed in our paper. First, we estimate the chance of meeting among nodes with direct and indirect meeting probability, and then the relay nodes are selected based on the meeting probability. Results show the proposed estimating method is accurate, and the performance of delivery ratio and delivery cost can be improved.