Increasing demands on contemporary men's underwear have affected the design method, including structure, knitted materials in accordance with male body morphology, comfort perception, and possible reshaping of soft tissues. The aims of this paper are to study body measurements to renew and to improve anthropometric and methodological databases, to classify the male lower torso into several size-based subtypes, and to refine body measurements for underwear design for the Chinese market. By means of scanning technology, we have obtained new information about male bodies’ morphology and established the sizing system for labeling of underwear in according with consumer demands. The new classification has two main levels and six stages to determine the lower torso and prominent local areas in the front and back. The new body measurements have improved the method of underwear design, making the underwear more comfortable and suitable for individual morphological features.