This article aims to explore the significance of the Upper Palaeolithic (UP) technological variation, against the backdrop of the general contention that the Korean UP is simply characterized by the manufacture of blades and small tools. Eleven lithic assemblages from the Imjin-Hantan River Area (IHRA) of the Korean Peninsula were selected to demonstrate this significance through an analysis of raw material exploitation and tool making patterns. The method of analysis is based on the approach that had previously been applied to earlier assemblages of the IHRA: the rank sequence method (RSM). The RSM calculates planar size, volumetric size, and elongation, using the metric dimensions of individual lithic specimens. These variables are allotted in descending order to form RS curves and their shapes and configurations are examined to interpret the function of sites, strategy of raw material utilization, and tool-making behaviors. The results of the RSM analysis illustrate that: 1) there are two patterns of lithic size distribution which indicate long-term occupation (PatternⅢ) with a palimpsest of diverse surviving behaviors and concentration on the manufacture of small-size (Pattern Ⅴ) lithic tools respectively; 2) the planar size distributions of small tools and blanks indicate both frugal (Pattern F) and parsimonious (Pattern P) consumption were dominant during UP in the IHRA; 3) the elongation of small tools and blanks indicate the manifestation of lateral reduction (Pattern LR), distal reduction (Pattern DR), and utility-first reduction (Pattern UF), and these three patterns reflect either the continuation of a previous technological tradition or the diverse output of hominin adaptations initiated from the UP of the IHRA. In summary, it is diagnosed that the UP of the IHRA shows diverse assemblage characteristics formulated by hominin strategic behavioral patterns that were implemented by knowledge of raw material availability and the demand for intended tool repertoires.