系统地总结与提出知识发现(KD)领域中当今面临的五类重大问题，它们是KD中的两大核心问题、两大猜想问题、主流发展中富有挑战性的问题、应用研究中的相关领域重大问题以及KD技术标准的制定问题，并给出其部分成果或具体分析。这五类问题密切相关，对它们的研究必将KD推向新的发展阶段,并在该领域内外产生深刻的影响。

In this paper, the author summarized and proposed five important issues in the present field of knowledge discovery and data mining, which comprise two important core issues, two conjectures, challenge issues in mainstream development, important issues of relevant fields in appliance research and technique standard in knowledge discovery (data mining).Some achievements and special analysis was also presented. Those five issues correlate closely, and these researches will push the development of knowledge discovery (data mining) to a higher stage, and bring great influence to the field inside and outside.