The social networks formed by distributed multi-Agent always show different characteristics. This paper proposed a social networks oriented collaboration degree based negotiation coalition formation mechanism aiming at the heterogeneity of different social networks and multi-Agent. This mechanism established a distributed negotiation protocol and designed a collaboration degree based negotiation tactic, which considered the characteristics of the social networks and the heterogeneity of the Agent. The experiment results in fully-connected network, hierarchical network and small world network have shown that this mechanism can form coalition in distributed environment effectively and show a better performance than other social networks in responding to small world networks in practical environment.