明洪武、永乐时期，对外政策由前者的闭关自守、严厉海禁，变化为后者的对外交往积极主动并宽驰“海禁”。两者相比较，存有明显的不同。显然，明成祖实行的对外开放政策，较之朱元津时期实行的对外闭关自守政策目光远大，合乎历史潮流。但不可据此简单地走下褒贬，应特别注意 Ming Hongwu and Yongle Periods, the foreign policy was self-restrained by the former and was strictly prohibited by the sea. It changed to the latter’s foreign exchange and took a pro-active and wide-ranging “ban on the sea.” Compared with the two, there are obvious differences. Obviously, the policy of opening to the outside world by the Ming Dynasty ancestors is far more historical than that of the policy of opening and closing the door of autonomy during the Zhu Yuanjin period. But it can not simply go down the line, should pay special attention