The recent paradigm shift in education is in progress. Until now, several subjects which have been little wonder about whether educate or not in the school, are made an issue from different standpoint. On this occasion, we judged that Korean education need to examine for the identity and the validity from the outside view. And we examine the status across the curriculum of Korean education because Korean education could continue advancing on a firm academic foundation when we establish the identity and the validity which distinguish from other subjects. For discussing about the cross-curricula characteristics of Korean education, we examined the instrumentality of Korean subject first. For this, we examine ze characters which technical tools and psychological tools have and concretize instrumental characters of the korean subject. And then we examined the cross-curricula characteristics which Korean subject has from the aspect of learning instrument. We discussed about how Korean subject mediate and accelerate the learning phenomenon through examining a number of studies. Finally, we proposed several directions which Korean education should take to firm up the status across curriculum. This article does not intend to assert that it is only whole thing that Korean subject should be tool-subject. That is not only right but also what we wished for. We merely propose to seek the possibility to expand Korean subject`s influence in the education and to recovery the cross-curricula characteristic of Korean subject. When ready to be that, Korean education could be developed on a firm foundation.