if u have american passport, u don't need any extra to enter HK or Macau; if u have greed card, u don't need any extra to enter HK or Macau, if ur staying is less than 10 days, beyond that u will need a visa.
if u have american passport, u don't need any extra to enter HK or Macau; if u have greed card, u don't need any extra to enter HK or Macau, if ur staying is less than 10 days, beyond that u will need a visa.