j1签证要多少保证金？
J1签证，全称exchange visitor exchange program， J=visa category. 来美学习或者来做研究，需要20万美金等值财产证明（存期一年以上）。这个存款的所有人必须是申请人本人，也就是说如果申请人和父母一起开一个共同储蓄户的话是不能用的。而且这个存款必须是申请人本人的名字存在银行里才有效。
我以美国国务院的官方说明为准，以下文字均摘自URL visa/j-1-visa.htm 我翻译如下： 所有在美国的Exchange Visitor，无论是来美国学习的还是做研究的，都必须在到达美国之前和入境之后向当地的美国移民局(immigration service office)或指定机构的代表出示其合法居留的证明文件。这些文件可以是下列其中的一个：I-94表格、I-94A表格或是移民机关发出的其他类似文件。持有F， J， M or Q签证的人必须保持他们的签证的有效期以及I-94的有效性直到他们离开美国或取得公民权为止。 如果您的签证是无效的在您到达美国的时候或在海关被检查的时候会面临遣返的风险，请仔细注意您护照上的签证条状物有没有正确的贴妥并且有效，同时注意它是否已经过期或被延期，注意海关人员是否有任何对它的更改。
如果您在美国留学，您可以得到两种合法居留的文件之一： I-20 Form (for the F Student status)， DS-2019 Form (for the J Scholar / Exchange Visitor Program participant， M Teacher of English as a Foreign Language status ) or DS-7001 Form (for those who qualify under certain M Visa categories). The I-20 for student and the DS-2019 for participants in J visas are issued by an Approved Designated School Official， sometimes called an "DSO" ， which is also your sponsor while you're here on an F， J， or M visa respectively. Your DSO has been approved to issue these forms by the U.S Department of Homeland Security， Immigration and Naturalization Service. When they receive their approval from INS ， they are sent copies of this letter along with instructions about how to use it to get an electronic Stamp in your passport that will allow them to issue you another form like theirs that says you have legal status as a foreign national studying or doing research in America until October 30th of the year listed next to its expiry date. The stamp expires ten years after it was first put into your passport by your DSO． If there’s no expiration date next to the year， then the stamp is good for only fourteen days after being printed． You should be sure when changing jobs that you transfer over to one that is sponsoring you so your new employer can send the old school a notice saying you left and what your new address is， so he doesn’t lose his sponsorship of you！ And if either your former DSO or your current D