In this article, I attempt to reconstruct the lithic reduction sequence of the microblade assemblage from the Okushirataki-1 site, Hokkaido, northern Japan, and to discuss the relationship between the technological variability of lithic reduction sequences and the morphological features of lithic raw materials, through with the assessment of numerous refitted materials. In terms of results, the refitted materials from this assemblage show that the detaching of microblades inevitably connects with the removal of blades in the course of the reduction sequence. Additionally, the presence and content of core preparations or rejuvenations on the flaked surfaces may have a significant role in the formation of variety among the blade and microblade reduction sequences. Therefore, it is not appropriate to compare the lithic assemblages and examine inter-site variability only through the analysis of morphological attributes reflected in the reduction sequence, which has been the focus of previous techno-typological approaches.