The present paper is to investigate the relationship between height and stress-bearing area of mandibular alveolar ridge, their influence on retention of complete denture, and the effectiveness of denture adhesive (DA). Five mandibular edentulous models of different heights and a rabbit palate model were prepared in Die-Stone. Measurements were made on the heights and stress-bearing areas of mandibular alveolar ridge, the retention force of mandibular models 15 min after DA administration, and the retention force on the rabbit palate before and after adhering. All available data were analyzed statistically. Linear regression relationship was demonstrated between ridge height and bearing area, ridge height and retention force, and bearing area and retention force (P<0.01), separately. Retention force per unit area was positively related to the height and area. Retention force increased to 2.87 times postadhesive-treating. Height and stress-bearing area of mandibular alveolar ridge directly correlate with the retention of complete denture, and DA significantly improves the retention ability of complete denture.