The operation principle and model of filtering for BPF were researched and how to use BPF to develop data filter system under Windows System was put forward.

• 研究了BPF的工作原理和过滤模型并且提出了在Windows系统下如何运用BPF过滤器开发包过滤系统。 BPF数据包过滤器在网络监控方面有巨大的研究和使用价值。