| 1 | At the beginning of the Qing Dynasty, Qing government followed the precedent policy of forbidding sea voyages. The major form of overseas trade was the tribute. | |
| 2 | Ming carried out the special policies of combining Tribute trade and Sea Forbidden, which strictly limited the non-governmental foreign trade. | |
| 3 | Soon after the Ming Dynasty had founded, the rulers of the Dynasty carried out strictly the maritime embargo as national primary policy. | |
| 4 | Zheng's voyage declared the end of ban on maritime trade in earlier Ming era, and the private business transactions at sea were flourishing day by day. | |
| 5 | In order to make a comprehensive view of the ups and downs in this 500-year-old history, we have to study this ban on maritime trade. |