Traditional methods for evaluating node importance in sustaining the overall network topology or information dissemination are widely studied

while most of them are not applicable to dynamic settings where connections among nodes change frequently over time.This paper treats an opportunistic mobile social network as a time evolved

dynamic graph and proposes an effective scheme to calculate the relative nodal dissemination capability based on the contact history.In particular

we analyze the node importance in forwarding messages in more general settings where messages are time-dependent and become less important or out of date over time.To this end

we take a dynamic walk counting approach to calculate all possible temporal-spatial routes from a node to any other node by using a method of down-weighting of length.Since the age of a message increases with time

the old walks are discounted to represent the fading influence on the destination nodes.Experiments are conducted based on 4 real-world trace datasets

and the results show that our analytical result is effective at ranking the capabilities of nodes in disseminating or receiving the time-dependent messages.