20国集团(G20)是一个国际经济合作论坛，于1999年9月25日由八国集团(G8)的财长在德国柏林成立，于华盛顿举办了第一届G20峰会，属于非正式对话的一种机制，由原八国集团以及其余12个重要经济体组成。
宗旨是为推动已工业化的发达国家和新兴市场国家之间就实质性问题进行开放及有建设性的讨论和研究，以寻求合作并促进国际金融稳定和经济的持续增长，按照以往惯例，国际货币基金组织与世界银行列席该组织的会议。20国集团成员涵盖面广，代表性强，该集团的GDP占全球经济的90%，贸易额占全球的80%，因此已取代G8成为全球经济合作的主要论坛。
G20的成立为国际社会齐心协力应对经济危机，推动全球治理机制改革带来了新动力和新契机全球治理开始从“西方治理”向“西方和非西方共同治理”转变。
2016年9月4日至5日二十国集团(G20)领导人第十一次峰会将在中国杭州举行，这也是中国首次举办首脑峰会。
Timothy Clancy,31, an Australian who has lived in Hangzhou since 2011 with his wife, who is from Zhejiang, said,"Australia has hosted such a summit before, but I never imagined that people in the host city could be so hospitable. I want to be part of this great event through the English classes and express my own welcome."
31岁的Timothy Clancy来自澳大利亚，妻子是浙江人，从2011年起两人开始在杭州定居。他表示："澳大利亚之前也曾举办过20国峰会，但是从来没有那个城市的市民像杭州这么热情好客。我想通过教英语参与到这个活动中来，同时也表达我自己对峰会的欢迎。"
Zhao Jihong,67, one of the senior students in Clancy's class, said,"I am learning English here just in case I come across foreigners so that I can at least say 'hi' to welcome them to Hangzhou."
67岁的赵继红是Clancy班上的一名大龄学生，她说："我学英语就是想有一天万一我在路上碰上了外国人，我可以跟对方打招呼，告诉他们杭州欢迎他们。"
Zhao Yide, the Hangzhou Party chief, said,"Thanks to the consistent efforts made by the people of Hangzhou, preparatory work for the G20 Summit has been a success. All services, including dining, transportation and security are in place. Hangzhou is now ready to host the two-day summit and welcome its distinguished guests."
杭州书记赵一德对此表示："感谢杭州人民为峰会作出的不懈努力，G20筹备工作已经准备就绪。包括餐饮，交通，安保在内的所有服务都已经安排妥当。杭州已经做好了迎接G20峰会的准备，准备好欢迎我们的客人。"
Non-G20 member countries such as Laos, Chad, Kazakhstan, Senegal and Egypt have confirmed that they will take part in the summit, according to the Chinese Ministry of Foreign Affairs.
外交部表示，老挝，乍得，哈萨克斯坦，埃及等非20国成员国均确认将出席此次峰会。
Zhao said the participants will have the chance to taste Hangzhou cuisine. A 7,450-square-meter warehouse is being used to store up to 900 tons of food, and all the food and ingredients will be bought, examined, monitored, maintained and delivered through this huge building.
赵一德表示，参会者将有机会品尝杭州当地菜肴。餐饮方面，杭州建设了7450平方米的食品总仓，总储量为900吨，对峰会的食材实行统一采购、检测、保管和配送。
Up to 900 vehicles are ready to transport the G20 leaders and their delegations. In addition,more than 2,000 drivers will be on duty to meet the needs of summit participants.
车辆保障方面，杭州为参会各国领导人以及各个代表团提供了约900辆车。此外，将有超过2000名司机在峰会期间在岗，保障参会者的出行需要。
Hangzhou Mayor Zhang Hongming said:"All previous hosts of G20 summits paid a lot of attentionto security, with troops and police fully prepared to guarantee this. Hangzhou is very confident of making the summit a safe event, and people are volunteering to be securityguards."
杭州市长张鸿铭表示："为了确保峰会的顺利举行，之前历届峰会举办国都在安保上投入了巨大精力，出动了大量的军队和警力。杭州可以很自信的说，此次峰会的不会有安全隐患，而且市民乐意为安保出一份力。"
A 760,000-member patrol group has been made up from local volunteers, according to Xinhua NewsAgency.