如果申请移民美国成功后，我在国内的教师职位还能保留吗？

其实可以，你每年可以在暑假，寒假来美国呆几个月，然后申请回美证，就可以省去半年这个规定。最主要是学校同意就行。因为如果你当老师的收入有5千以上，就没必要辞职过来。我朋友在广州的医院当护士，她就是这样一直干到退休才过来长住。另外你长期在国内上班，还要考虑年底报税（交给美国政府），祝你好运。

--记住主要是学校同意你这样干。

1楼的对美国的永居身份居住要求一点都不了解，不要误导人家。

美国的永居身份即绿卡身份要求是每次离开美国不超过一年，你可以利用假期的机会登陆美国就可以了，完全没有任何问题。即便是要离开超过一年，可以在离开美国之前申请回美证即可。还有就是要纳税，就可以维持身份了。

所谓半年之说是在入籍的时候计算居住时间的，每次离开美国不能超过半年，而维持绿卡身份是不需要的。

这是美国公民移民局网站上的文字供你参考：
Maintaining Permanent Residence

You may lose your permanent resident status (green card) if you commit an act that makes you removable from the United States under the law, as described in Section 237 or 212 of the Immigration and Nationality Act (INA) (see the “INA” link to the right). If you commit such an act, you may be brought before an immigration court to determine your right to remain a permanent resident.

Abandoning Permanent Resident Status

You may be found to have abandoned your permanent resident status if you:

Move to another country intending to live there permanently
Remain outside of the United States for more than 1 year without obtaining a reentry permit or returning resident visa. However, in determining whether your status has been abandoned, any length of absence from the United States may be considered, even if less than 1 year
Remain outside of the United States for more than 2 years after issuance of a reentry permit without obtaining a returning resident visa. However, in determining whether your status has been abandoned any length of absence from the United States may be considered, even if less than 1 year
Fail to file income tax returns while living outside of the United States for any period
Declare yourself a “nonimmigrant” on your tax returns
http://www.uscis.gov/portal/site/uscis/menuitem.eb1d4c2a3e5b9ac89243c6a7543f6d1a/?vgnextoid=3f443a4107083210VgnVCM100000082ca60aRCRD&vgnextchannel=3f443a4107083210VgnVCM100000082ca60aRCRD

很不现实！

你移民后是绿卡，你一年要有最少半年的时间在美国

超过半年，没有可信的原因，你得绿卡就自动作废了

中国的学校能让你只工作半年么？

长此下去，也不是个办法呀！