The 1985 Schengen Agreement is an agreement among most European countries which allows for the abolition of systematic border controls between the participating countries. Covering a population over 400 million and a total area of 4,268,633 km², it includes provisions on common policy on the temporary entry of persons (including the Schengen Visa), the harmonisation of external border controls, and cross-border police co-operation. By the Treaty of Amsterdam, the agreement itself and all decisions having been enacted on its basis had been implemented into the law of the European Union.
A total of 30 states, including all European Union states and three non-EU members (Iceland, Norway, and Switzerland), have signed the agreement, and 24 have implemented it so far. Ireland and the United Kingdom only take part in the police co-operation measures and not the common border control and visa provisions. Border posts and checks have been removed in the Schengen area[1] states (see section Customs control) and a common Schengen visa allows tourist or visitor access to the area.
《申根協定》(德語：Schengener Durchführungsübereinkommen)，亦称《申根協議》、《申根公约》或《申根公约》，最早于1985年6月14日由五个欧洲国家（联邦德国，法国，荷兰，比利时，卢森堡）在卢森堡的一个小城市申根（Schengen）签署。该公约于1995年7月正式全面生效。
《申根公约》的成员国亦称“申根国家”或者“申根公约国”，成员国的整体又称“申根区”。《申根公约》的目的是取消相互之间的边境检查点，并协调对申根区之外的边境控制。即在成员国相互之间取消边境管制，持有任一成员国有效身份证或签证的人可以在所有成员国境内自由流动。根据该《协定》，旅游者如果持有其中一国的旅游签证即可合法地到所有其他申根国家。
《公约》签订以后不断有新的国家加入进来，截至2007年，申根的成员国增加到24个：奥地利、比利时、丹麦、芬兰、法国、德国、冰岛、意大利、希腊、卢森堡、荷兰、挪威、葡萄牙、西班牙、瑞典、爱沙尼亚、拉脱维亚、立陶宛、波兰、捷克、匈牙利、斯洛伐克、斯洛文尼亚和马耳他。这些国家是今天的申根区。申根国家中除挪威和冰岛之外均为欧盟国家，相反英国和爱尔兰是欧盟国家，但不是申根协定的成员国。
2006年12月5日，欧盟各国主管内政和司法事务的部长级官员在布鲁塞尔开会决定2007年12月31日起吸收于2004年5月加入欧盟的10个国家（即爱沙尼亚、拉脱维亚、立陶宛、波兰、捷克、匈牙利、斯洛伐克、斯洛文尼亚、马耳他和塞浦路斯）加入《申根协定》。 根据各国达成的安排，欧盟将分步骤吸收10个新成员国加入《申根协定》。这些国家与15个现协定国之间的陆路和海路边卡于2007年12月开始撤除，而机场边境检查也将在2008年3月30日起取消，只有塞浦路斯和马耳他要求保留部分边境管制措施。瑞士于2005年6月5日举行全民公投，以些微差距通过了《申根协定》，决定于2007年实施加入“申根区”，但有東歐居民會引致擔心西歐國家（特別是英國）罪案和非法移民情況於2010元旦假日趨嚴重。
Isn't it cool? Passport-free travel. The people of those countries can freely travel amongst the countries without any troublesome of application of Visa. It is definitely a great news to the people, as well as the businessman. The flow of potential customers from different countries will bring more profit to the companies. However, it may bring some problems to the countries as well.
In my opinion, it can bring a poor economy to those less-developed EU member countries especially when they are lack of attraction. They may fail to attract potential tourists or investors to their countries. Reversely, their people will spend their currency in other countries. Thus, their value of currency will drop, in other words, a depreciation of currency. Besides, the freedom of flow of people may cause some population issues. For example, it is difficult to track down a Germany murderer if he has escaped away to other EU countries. Moreover, more people of other countries may flood into those developed areas for searching a better standard of living. It could bring unnecessary pressures on those areas in terms of safety, hygiene and medical. Definitely, it leads to a competition of raw materials and human resources among the countries. SO, does this agreement bring more pros than cons to its member countries, I don't know. But, I am sure that it must be a great news to their people who love travelling.
