Base on study the existing network security theory and techniques and the analysis of the FTP Protocol, there are holes in FTP due to its transmission of plain data, data contents are easily tapped.

• 本文首先研究了现有的网络安全理论技术,接着分析了FTP协议,指出协议安全漏洞主要体现在明文传输数据,数据内容容易被窃听。