The present invention relates to a method for fabricating a three-dimensional porous fibrous microstructure, various three-dimensional porous fibrous microstructures fabricated by the method, an apparatus for detecting a biological marker and a drug delivery system comprising the microstructure. The porous fibrous microstructure of the present invention has excellent interconnectivity between pores and micropores and captures and delivers target particles at high efficiency, and thus can be usefully applied to biomedical applications including the detection of a biomarker and drug delivery.