係唔係一定要在半年去一次美國 ,如果我剛剛攞咗美國簽証?

which kind of 美國簽証?
How long is your 簽証?
If it's a B2 visa, don't worry, you can travel within the permitted period. for example, if you have 10 years, you can travel during that timeframe

If it's other type of visas, you need to be during the certain kind of activity permitted. for example, for f1 visa, you need to be a student, etc. you can e-mail me for more info.

the type that requires you 半年去一次美國 is not a 簽証, it is a permanent residence green card. so, if you have a green card, yes; but if you have citizenship, you don't need to do that any more

hope it helps.

2008-03-19 01:14:05 補充：
all these ' above are ' marks

不需要的，除非你的簽證限期只有半年。
舉例，假如取得了十年的簽證，即代表由簽證那天開始計算，十年內有效，在十年內都可以去美國旅遊。

當然，在簽證限期內都無去過美國，下次申請時會否增加不必要的難度，那就要看領事館的決定了。