During negotiating process of drawing up global environmental conventions or protocols, negotiating parties to form different negotiation coalitions can be observed. However, few existing academic literature or studies have taken a systematic approach to explore the elements that contribute to the formation of these coalitions and to the changes of coalitions in the middle stage of negotiating process. Through examining the negotiating process of several selected conferences for the establishment of global environmental treaties which are representative in nature and from different international environmental domains, this study is to find the core elements and sub-elements which contribute to the formation of negotiation coalitions. This study shows that the composition of negotiation coalitions is dynamic. The timing of reorganizing the negotiating coalitions falls on the stage in which negotiation proceeds from principle issues to substantive ones. In other words, when the issues under negotiation begin to involve legally binding substantive commitments to State parties, the reorganization of negotiation coalitions emerges. Furthermore, this study also finds that common elements do exist in the formation of negotiation coalitions. The core elements are ¡§the source of threat¡¨ and ¡§enhanceing the influence of a State¡¨; they are not affected by the change of negotiating issues. The other two sub-elements are: ¡§the same experience of participating in the same international organizations¡¨, the factor for forming negotiation coalitions during the stage of negotiation on principle issues, and ¡§domestic economic structure¡¨ during the stage of substantive issues negotiation for the formation of negotiation coalitions.