National cultural security has become a hot topic of research in recent years. The first step of the research, like many others on national strategy, is to identify current challenges to cultural security with which China is faced. Relevant published articles in China usually assume the pattern of "problems plus countermeasures" which includes connotations of cultural security, strategic significance, roots of problems, current challenges, and approaches and countermeasures. Their titles are often generic without distinct standpoints. All of this shows that the study of cultural security is still at a primary stage where a cover-all discussion is typical. Given that the overall review about it has been gradually improved, we should move on to the identification of basic theoretical issues, which unfortunately turns out to be a bottleneck that requires a diversion from macro and overall approaches to micro and segmental observation. In fact, to reach a high-level and comprehensive solution for issues about the cultural security of China relies on an in-depth theoretical study and a detailed comprehension about specific aspects of it. For this reason, it is necessary to begin with defining national cultural security and probing into the most basic theoretical issues such issues as decisive variables, spatial dimension, inner structure, and exterior relations.