After arriving at Hongkong Airport from Portugal, can I go to Macau directly by boat with China passport and Portuguese residence certificate?

But I don't fully understand your question.

Are you going to stay in Macao all the time? Or just stay in Macao for a few days?

In your case, you can go to Macau, but only in the name of transit.

Stay in Macau for 7 days (with your China passport and Portuguese green card).

If you want to live in Macao for a long time, you must find a job in Macao and go through the residence formalities.

However, if you come back speaking Portuguese, it is very easy to find a job in Macao.

PS: If you have a green card, you can apply for a long-term entry visa to Hong Kong at the China Embassy or Consulate in Portugal.

Valid for two years, no entry restrictions, one-time stay 14 days.

It's ok to go to Macau with a Hong Kong visa, and 14 days is unlimited.

For details, please consult the Embassy and Consulate of China in Portugal.

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Absolutely. Your green card is like a visa.

You can stay in Macao for 7 days.

However, I suggest that for your convenience, you can apply for a long-term Hong Kong visa to go to Macau. China citizens with the right of abode in foreign countries can also apply for such visas.