Teacher 8 and all, please help: travel from Europe back to US

green card holder, plan to use Canadian passport travel to EU, when back to US:
1. need to have green card with a valid passport? Not only green card?
2. any problems of dual nationalities? Before only used chinese passport to China, Canadian passport never has been used. So record in US is chinese citizen with US green card. 
3.In general, is it always feasible to use chinese passport back to China, while use Canadian one traveling to countries where PRC are required to apply visas?
Thanks a lot!

所有跟帖： 

• 回複：Teacher 8 and all, please help: travel from Europe back to US -863211- ♂ (791 bytes) () 08/21/2013 postreply 09:37:26

• Thanks! How about answer for question 2 &3? -小小同學- ♀ (250 bytes) () 08/21/2013 postreply 11:56:17

• 回複：Thanks! How about answer for question 2 &3? -863211- ♂ (696 bytes) () 08/21/2013 postreply 13:38:41

• 回複：回複：Thanks! How about answer for question 2 &3? -小小同學- ♀ (0 bytes) () 08/21/2013 postreply 13:48:12

• 回複：回複：Thanks! How about answer for question 2 &3? -小小同學- ♀ (291 bytes) () 08/21/2013 postreply 13:50:39