In this paper, we study the Prisoner's Dilemma Game (PDG) on a scale-free social network where the agents participate the game with a probability proportional to the power of their degree, i.e., Pi ~ kαi. In this way, the agents' participation in the game change with time, and our study reveals some properties of PDG in a dynamic social structure. In the generations each active player updates its strategy by following one of the active neighbors' strategy with a probability dependent on the payoff difference. Simulation shows the dynamic
attending of agents has an important effect on the evolutionary game. In order to enhance cooperation behavior,
we need to constrain participant of low-degree agents and encourage participant of high-degree agents in the
game. In most cases, a maximum cooperation frequency is achieved when α is set to be slightly higher than
zero. Our study may also shed some light on the policy construction of government.